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Colon and Rectal Cancer

Side Effects of Treatment

The following excerpt is taken from Chapter 11 of Colon & Rectal Cancer: A Comprehensive Guide for Patients & Families by Lorraine Johnston, copyright 2000 by O'Reilly & Associates, Inc. For book orders/information, call (800) 998-9938. Permission is granted to print and distribute this excerpt for noncommercial use as long as the above source is included. The information in this article is meant to educate and should not be used as an alternative for professional medical care.

Why do side effects arise?

Side effects of treatment can arise for several reasons.

First, the treatments commonly used today for colorectal cancer affect not only cancerous cells, but many healthy cells as well. Radiotherapy and many chemotherapy regimens target cells that divide rapidly, as many cancer cells do. This targeting of fast-growing cells means that many healthy cells that divide rapidly--cells in the mouth, intestinal tract, hair, fingernails, and others--will be affected, too. During treatment, these cells die all at once, instead of passing through the life cycle just a few at a time. This rapid turnover of cells causes some of the most common side effects of cancer treatment, such as mouth sores and hair loss.

Other side effects come about owing to the body's attempt to heal itself. Tumor lysis syndrome, for instance, is a side effect of the body's attempt to clear itself of dying tumor cells after certain treatments.

Many side effects of treatment are normal and pose no danger to you. Fatigue and changes in fingernail growth are common side effects of treatment that do not necessarily herald problems. Your oncologist should give you fact sheets to provide you with information about side effects that are very serious, and about which you should telephone as soon as you notice them. If your doctor doesn't offer this information, ask.

I had CPT11 for a year. I didn't have too many side effects. I took the CPT11 together with 5-FU and leucorovin. I didn't lose my hair and unfortunately, didn't lose any weight either. In fact, I gained 30 pounds. When I am given my chemotherapy, the doctor also puts in a Kytril and Decadron drip. This completely eliminates any nausea, at least for me. I have been off chemo for four months now, so I am hoping when I get back on it, it doesn't affect me differently since the first go-round was relatively easy.

Side effects by type

Listed alphabetically below are many side effects of treatment. Although great variability exists in patients' reactions to treatment, the most commonly occurring are nausea, diarrhea, abdominal cramping, mouth sores, hair loss, and fatigue. Included within the various sections below are tips from colorectal cancer survivors for dealing with side effects.

Abdominal pain

Abdominal pain or cramping is common following surgery, chemotherapy, or radiotherapy for colorectal cancer.

As abdominal pain also can be a sign of intestinal blockage owing to tumor regrowth, you should notify your doctor of this pain, especially if cramping persists or worsens.

Many good medications are available for abdominal cramps, ranging from mild over-the-counter remedies to narcotic substances, but often what works for one patient does not necessarily work for another. Ask your doctor for an appropriate treatment, and be persistent until a good remedy is found.

Dietary changes sometimes are helpful in controlling abdominal cramps. Some patients have found that dairy, soy, fat, or wheat gluten products are not tolerated well following treatment for colorectal cancer. Modify your diet slowly and judiciously, and only with your doctor's approval.

Various other causes of abdominal pain exist, and are discussed in the subsequent sections of this chapter.

Randall describes abdominal pain that persists several months after surgery:

My colon resection was many months ago. I still have gastroenterologic weirdness. I'm talking stools, gas, and cramps. No blood in stools, but not "normal." The first couple of weeks after surgery, things were back to normal. First time in two years. But then...

My colon-rectal surgeon says that there is usually a tightening of the colon at the anastomosis, or "that-place-where-the-two-healthy-ends-of-colon-were-stitched-back-together." As it heals, it constricts. As it constricts, size, frequency and other characteristics of stool change. He had me doing high-dose Metamucil to try and "stretch" the opening back out. So far, no progress. My anastomosis is located about halfway down of what is left of the descending colon.

Occasionally, I will have fold-me-in-half cramps in my lower gut which immobilize me until I can get to some place where I can at least pass gas.


Following radiation therapy for rectal cancer, abscesses within the pelvis may develop. This usually occurs as a late effect if at all, but may develop earlier in certain people.

If you have unusual and pronounced pain, fever, nausea, difficulty with bowel movements, or the appearance of pus from the vagina or rectum, notify your doctor immediately.

Acid indigestion (See Nausea)

Allergic reactions

It's possible to have an allergic reaction to almost any drug, depending on a host of poorly understood factors. Allergic reactions are more likely to occur with high doses of a drug that is administered rapidly.

In the past, most allergic reactions were detected in the doctor's office as chemotherapy was being administered through an IV line by drip bag or bolus push (a bolus is the back end of a syringe, the reservoir that holds the medication). With the advent of the continuous infusion pump, however, it's possible to have an allergic reaction at home, hours or days after the pump has been restocked with medication.

Allergic reactions are highly individualized to substance type, but the symptoms are similar and include any of these: hives; itching; difficulty breathing; tightness in chest or throat; sore throat; fever; or chills.

Appetite or taste changes

Chemotherapy and radiotherapy can affect your taste buds to the extent that you can't taste food, or that it tastes metallic or even disgusting.

I find so many of the foods I used to love are now repulsive. Even stopped adding sugar to my decaf. Sweet is too sweet. This scares me more than the cancer. I always liked to eat, now I'm avoiding meals in any way I can.

I just had breakfast that consisted of two slices of whole-wheat toast and butter. Still like the taste of salted butter, thank God.

Adequate nutrition in spite of food aversion is a very important part of your recovery. Eat what you like, but eat as much nutritional food as you can. Ask your doctor about vitamin supplements and liquid supplements such as Nutrical or Ensure.

We went to a wedding today and I thought I wouldn't be able to have the good time I used to have at affairs. Too many things driving me down: fatigue, lack of appetite, and now a little depression over the whole situation. I haven't had diarrhea in a week, so at least that's good. Hey, there is a bright side.

I took Zofran and Imodium tablets before leaving for the wedding, and in an hour or so, the pill kicked in, I regained my appetite and lost most of the nausea just in time to enjoy the wedding. I had the chicken. Maybe for the first time in my life I'm eating "healthy." (That's when I can eat.)

I praised the Zofran god last night. I still have seven sample pills left and will ask my doctor for a prescription this Wednesday.

Some colorectal cancer survivors note that, rather than craving particular foods, they are repelled by them, particularly by meats. Foods that once were favorites now have repugnant or metallic taste and scent.

I am on 5-FU with leucovorin and the taste bud problem has been progressive. I find that some foods totally turn me off now. I used to love meat, but now have no taste for it. I used to love bacon cheddar cheeseburgers! The idea turns my stomach now. Used to love especially sweet drinks, can't stand them now, they almost make me gag.

I like salt now more than ever. I have a desire for a hot dog, but I'm afraid to try it because that too might taste different. Had pizza last night and at least that still appeals to me. I hope I never lose my taste for pizza. One of my joys in life was eating; now it seems a chore.

Blood clots, pulmonary embolism

At the beginning of treatment, a large abdominal tumor may shrink rapidly in response to therapy, and may dislodge a pre-existing blood clot. Blood clots also may form around a central catheter at any time during treatment.

If you have a central catheter, or have a large abdominal tumor and have just started treatment, be especially aware of deep pain or difficulty breathing that may signal a dangerous blood clot dislodging, or capable of dislodging and traveling to the lung.

Bone pain

The colony stimulating factor G-CSF (Neupogen, Filgrastim) can cause aching bones and joints. Ice packs may relieve this pain; if not, ask your doctor if the dose can be lowered. Bone pain associated with G-CSF is temporary.

Severe back pain may be associated with degenerative changes to the spine following radiation therapy. The spine is not able to sustain as high a dose of radiation as some other organs can. Surgery to fuse spinal discs may alleviate this pain.

Bone pain should always be reported promptly to your doctor, as colorectal cancer can travel to and lodge in bone, and can affect abdominal and pelvic nerves that cause pain in the spine.

Bowel obstruction

Following surgery or radiation therapy for colon or rectal cancer, one or more bowel obstructions may develop and persist over time.

Bowel obstruction is a painful, life-threatening event. Contact your doctor immediately if you have difficult or absent bowel movements, pain, fever, or a small amount of diarrhea in the presence of these symptoms.

An ostomate describes how a less-careful diet almost caused him serious problems:

You can eat things that will block your intestine and keep things in there for much too long. Then you need to go out and get the medical equivalent of Drano or a sump pump. I ate raw pecans and my digestive tract wasn't quite up to that yet, and it got about 95 percent through and stopped, and the intestine got distended. They literally go in with a tube and suck out what's clogging things up. I wasn't admitted to the hospital for this. I went to the ostomy nurse and said, "I feel bad," and pointed to my stomach. They said, "Yeah, you screwed up." They go through the stoma with a tube about six inches long and an inch in diameter and flush water in--I think 100 ccs--then they suck it out and loosen up whatever's there.

If you have an ileostomy, only a blockage makes it hurt. The nerves in the small intestine seem to be much different from the large intestine. Things like volume and pressure of gas buildup don't hurt like they do in the large intestine. The small intestine just keeps pushing things on through. It doesn't hold material like the large intestine.

Breathing problems

Call your doctor immediately if you have trouble breathing.

Many treatments for colorectal cancer, such as monoclonal antibodies, radiation, or certain chemotherapy drugs that affect the heart, such as 5-fluorouracil, can cause difficulty breathing.

Rapid breathing (tachypnea) can be the body's effort to lower levels of excessive acid, called acidosis. Acidosis is a very early sign of certain conditions such as serious infection, kidney damage, or diabetic complications that should be treated immediately.

Rarely, circulatory or respiratory distress can be linked to untreated, intractable constipation.

Bruising, bleeding

If your chemotherapy is administered directly to the liver via portable infusion pump, you might experience gastrointestinal bleeding, which should be reported to your doctor immediately.

See also Pancytopenia.

Chest pain

Report this symptom to your doctor immediately.

Those receiving 5-fluorouracil therapy may experience a constricting type of chest pain known as angina.

See Heart damage.

Cognitive changes

Many patients report that treatment makes them feel fuzzy-minded or forgetful. These symptoms should go away over time.

Rarely, more serious cognitive changes may occur. Fluorouracil and certain platinum-containing drugs are capable of causing delirium or dementia.

Call your doctor if these symptoms are very disturbing, or if you or a loved one feel that these side effects represent a danger to the patient or the family.


Constipation can be a very serious problem during colorectal cancer treatment, because inactivity, tumor regrowth, other illnesses, and certain drugs such as painkillers, antidepressants, or antihistamines may slow or paralyze the intestine, or mask the urge to move one's bowels.

Constipation in its most serious form, a total blockage of the intestine called fecal impaction, can present as circulatory or respiratory distress. Call your doctor immediately if you feel constipated for more than three days, or if you have difficulty breathing or symptoms of heart failure. Fecal impaction can be fatal even in the absence of a tumor.

If your doctor agrees, experiment with small amounts of different foods until you have a sense for what will maintain a balance between constipation and diarrhea. This balance is especially important directly after surgery, when dietary roughage can cause too much soft stool before adequate healing has occurred.

Increased fluid intake, regular exercise, increased dietary fiber, warm or hot drinks, privacy and quiet time in the bathroom, easy access to toilet or bedside commode, and stool softeners may be tried to ease constipation. Do not make dietary changes or greatly increase your fluid intake without first verifying these choices with your doctor.


If you suspect you are dehydrated, call your doctor immediately.

Dehydration is a very serious side effect of vomiting or diarrhea, for cancer patients must have adequate fluid to remove from the body toxins as well as proteins released by dying cells. Moreover, the quantities of electrolytes and minerals such as phosphorus, calcium, potassium, magnesium, and sodium may be disrupted in the colorectal cancer patient, both by disease and by treatment. Dehydration exacerbates this imbalance.

The most reliable symptom of dehydration is thirst. Other signs include the inability to urinate about once an hour, the production of very little urine, or the production of urine that is both dark and low in volume. Other symptoms, such as faintness, dry lips, thick saliva, or loss of appetite resemble the side effects of some chemotherapies too closely to be reliable indicators of dehydration.

Take in as much fluid as possible, but do not drink products containing electrolytes (as do the products marketed to sports enthusiasts) unless your doctor says that your kidneys are in good condition and that these drinks will do you no harm.


Removal of most or all of the large intestine frequently results in diarrhea. Radiotherapy targeting the abdomen or chemotherapy also may cause diarrhea, as dying cells are shed from the intestine.

About halfway through my chemotherapy treatments I suffered terrible diarrhea. I thought my colon would turn itself inside out. The oncology nurses kept telling me the usual things like low fiber, small frequent meals, no dairy, and so on, and had me taking double, then triple strength doses of Imodium. This was useless! Finally my oncologist prescribed Lomotil twice daily. It only took about three or four doses to get it under control. After that I only took it as needed.

Phone your doctor immediately if diarrhea is combined with a fever more than 1.5 degrees higher than your normal temperature, general malaise, severe chills, night sweats, burning or pain while urinating, headache, neck stiffness, coughing, or trouble breathing.

Your doctor can recommend anti-diarrheal drugs, which you will have to balance carefully with drugs such as stool softeners to control constipation. Experiment with small amounts of different foods until you have a sense for what will maintain a balance between constipation and diarrhea.

The dietician, whom I met with weekly, and the doctor gave me a restricted-residue/low-residue diet that really helped when the multiple bowel movements returned from irritation from radiation. I never really got bad diarrhea once I started on the diet.

As treatment neared its end, my hemorrhoids flared up terribly and my doctor gave me Anusol HC suppositories. Ah, relief.

Administration of the drug CPT-11 (irinotecan) can cause immediate diarrhea in some people. Addition of atropine offsets these symptoms.

My husband had diarrhea during the cycle, but managed pretty well. He had a positive response to the drug that made it easier to tolerate. It is very important to have an oncologist who will listen to your concerns and adjust things to meet your needs.

•  •  •   •  •  

One side effect of radiation was diarrhea. I couldn't be too far from a bathroom; my back end got really sore. I used baby wipes, the non-alcohol type, and Balmex cream. You can find both in the baby aisle of your drug store. Both were a godsend, as were the sitz baths. If you don't have one, get one, plus a reading rack for the bathroom with your favorite magazines or books.

Dry mouth, difficulty swallowing

Chemotherapy for colorectal cancer can at times cause dry mouth.

Normal saliva contains an antibiotic. In the absence of saliva, dry mouth can lead to serious dental problems that result in whole-body (systemic) infection and tooth loss. Thus, gentle but scrupulous dental care is a must. Avoid spicy, sour, or acidic foods. Examine your mouth daily for fuzzy white patches that might be a fungal infection. Ask your doctor for drugs to increase saliva flow, or for instructions for a homemade mouth rinse that can be used several times a day.

Marsha Center, RDH, describes her dental care during treatment for colorectal cancer:

I am a registered dental hygienist who has worked 20 years in private practice. I was diagnosed with colon cancer, had a resection and six months of continuous infusion of 5-FU through a Groshong catheter. While I was undergoing the continuous chemotherapy my oncologist cautioned me about any dental work, especially not to have my teeth cleaned. The problem is the introduction of bacteria into the blood stream via the sulcus area surrounding the teeth. That in turn could travel to the central catheter or weak point in my body. Then infection would develop, requiring removal of the port, massive doses of antibiotics, and so on. So I waited to have my teeth worked on until I was through with chemotherapy. I am not a periodontal patient, but this caution is even more significant for those who are.

As far as discomfort, the dentist or even the oncology staff should have access to products [that can help]. I had mouth sores that made eating uncomfortable. A rinse made by the oncology pharmacist made of benzocaine, tetracycline, and other bacteriostatic ingredients was extremely helpful. Peridex has chlorhexadine in it which kills bacteria in the mouth, but also contains alcohol, and that was a no-no for my mouth, because it's too strong. Some fluoride preparations can also be helpful.


Sometimes, chemotherapy that is administered by IV or catheter can leak out of the vein into surrounding tissue, an adverse event called extravasation. The reaction of the body to a high concentration of chemotherapy in the skin or other tissue can be serious and painful. The artery or vein may be unusable for chemotherapy thereafter; the skin may die, slough off, and fail to regrow.

Symptoms of extravasation include pain, redness, swelling, or burning at the IV or catheter site, during or after the administration of chemotherapy. Notify the medical staff immediately if you have these symptoms during or just after treatment.

Eye changes

Administration of the drug CPT-11 (irinotecan) can cause production of excess bodily fluids in some cases, manifesting as watery eyes. Addition of atropine offsets these symptoms.

Administration of the drug 5-fluorouracil can cause watery or dry eyes.

Eye drops might help with these problems. If they do not, you might consider consulting an ophthalmologist who is a lacrimal (tear) specialist. In extreme cases, a surgery can be performed to reopen scarred tear ducts.

About seven months into my treatment I started experiencing constant tearing from my right eye. My ophthalmologist said I had very small tear ducts, she probed it, and everything was fine for about a week, when the left eye began to tear.

After repeated probing failed to correct the problem, she sent me to a lacrimal specialist. (I didn't even know such a specialty existed.) My oncologist said this was totally unrelated to the chemotherapy. However, when I saw the lacrimal doctor, his first comment was to ask if I was taking 5-FU. I have since had duct surgery (ouch! I'd rather have another bowel resection), and I possibly face reconstruction surgery in the next few months.

Fainting, lightheadedness, dizziness

Although dizziness is a known benign side effect of many drugs, these symptoms can be serious side effects of chemotherapy. Notify your doctor immediately if you experience these symptoms.

Fatigue and sleep disorders

Those being treated for cancer list fatigue as the most debilitating symptom they experience. Ninety-five percent of those being treated for cancer report fatigue.

Shelly Weiler describes his difficulty dealing with fatigue:

I used to have only about two or three throwaway days, as we call them. Now I'm having as many as five throwaway days in a seven-day week. The fatigue is so overpowering I can't really describe the feeling. It leaves me lifeless at times and all I want to do is sleep. To me it feels like I could suddenly sleep standing up. It comes on rather quickly and is totally overpowering. This is more scary to me than having the cancer.

At first I even believed I would eventually get back to work. As the time goes on this has become more than impossible because of the fatigue. I couldn't possibly work a full day five days a week. If I went back to work even for one day a week I'd lose my disability benefits.

I know there are a lot of caregivers who have loved ones experiencing this fatigue. It can't be described as being "tired." That's different. It's not like being tired from working hard or having a long day.

It's more like a hood has been put over your head and you are experiencing almost an out-of-body experience of complete body exhaustion. It comes on suddenly, and sometimes just a quick nap lifts the cloak from your head and you feel refreshed. At other times it's enough to put me to sleep for nine to twelve hours. My muscles don't ache from overwork or exhaustion, it's just a drained feeling. At these times I'm too tired to eat even if I'm hungry. I'm actually having difficulty describing the feeling, but I'm sure all cancer survivors know what I'm trying to express in words.

I sometimes sit here and cry when I feel the fatigue overtaking me. I literally have tears rolling down my face. My wife will say, "Shelly, are you okay?" I just answer, "The fatigue is killing me. It doesn't let me enjoy the life I have left." I'm in no pain from either the colon surgery nor the liver damage from the disease.

Here it is almost 8:00 AM and I've been up since 5:00 AM; slept last night about nine hours. I feel like I haven't slept at all. Does this feeling ever go away? There is so much I want to do today and my body is just not ready.

While being treated, you may be able to offset some of the effects of fatigue on well-being and performance by getting as much rest as possible, eating well, and exercising moderately. Nonetheless, you may do best to adjust your demands on yourself to these new circumstances: let the less critical things go, and attend only to what matters the most.

Symptoms of fatigue should improve after treatment ends; however, many cancer survivors report fatigue years after treatment.

Sleep disorders also are common, and in some cases persist years after treatment. Insomnia, "night horrors," and corresponding daytime sleepiness plague many colorectal cancer survivors.

Because fatigue can have so many causes--nutritional deficit, drug interactions, tumor activity, tumor death, inability to exercise, depression, changed sleep patterns--it is difficult to treat fatigue with other than trial-and-error methods. Ask your doctor for suggestions for dealing with this problem, and see Chapter 12, Stress and the Immune System, for additional ideas.

A web site staffed by oncology nurses for cancer survivors suffering from post-treatment fatigue can be found at

A discussion group for those suffering from cancer fatigue exists on the Internet. Visit to enroll in the Cancer-Fatigue discussion group.

Fever, chills, sweats

Fever should always be reported to your doctor, especially if other signs of illness accompany fever.

Fever can be the first symptom of life-threatening infection when white blood cells have been destroyed by therapy. Unattended fever in the absence of sufficient white blood cell numbers can be fatal, and is a medical emergency requiring immediate attention.

After my first treatment I experienced neutropenia and was hospitalized for five days in isolation and received antibiotics IV. Yuck! During this time they started me on G-CSF ( granulocyte colony stimulating factor) to help the white count. The doctor decided to keep me on these shots after the remainder of my treatments. He said most people don't get neutropenic from these treatments, but he thought I might have between the radiation and starting treatments perhaps a little too soon after surgery. I would give myself the shots for four days, beginning two days after chemotherapy ended. One time per day was not bad after the first time I did it.

I did become very neutropenic again after the last treatment, but my doctor did not make me stay in the hospital. I just had to go in every day for five days and get IV antibiotics. During this time I also developed a blood clot so I went on blood thinners for six months.


After surgery, chemotherapy, or radiation therapy--or simply as a result of disease in the abdomen or pelvis--an abnormal tubelike connection called a fistula can form between internal organs such as the bladder and the vagina.

If you notice unusual discharges, such as urine leaking from the vagina or fecal material or odor when you urinate, notify your doctor at once.

Hair loss and growth

Radiotherapy and many chemotherapeutic agents cause hair loss--alopecia--although there is a wide range of individual responses to treatment in this regard. Some people lose just a little hair; others lose all hair, including body hair, eyebrows, and eyelashes. Others report losing grey hair earlier than hair that contains pigment. Those receiving radiation therapy may lose hair only on the spots irradiated, such as pubic hair.

New hair should regrow in the weeks or months after treatment. In some instances, it might not regrow, although this is more common after radiotherapy than after chemotherapy.

Methods to spare the scalp from exposure to chemotherapeutic agents, such as ice-packing or tourniquets, are not recommended, because small amounts of cancer may be sequestered in the skin or blood vessels of the scalp. Denying chemotherapy the opportunity to kill all colorectal cancer cells may result in failed treatment or relapse.

Conversely, interferons sometimes used for colorectal cancer may cause excessive growth of hair, called hirsutism. Some women taking interferon-alfa-2B report growing long eyelashes for the first time in their lives.

Sue Browne retells her husband's experience with chemotherapy:

Chemotherapy was to start five weeks after surgery. His chemotherapy was the standard first-round therapy, 5-FU plus leucovorin. After four months, it was determined that this was not doing anything, and that the tumors in his liver had continued to grow. This was too bad, because he was tolerating this chemo pretty well, with only slight fatigue and some diarrhea, which we could control with medications. (It has been determined that side effects and treatment efficacy are not related; in other words, just because one has no side effects does not mean the treatment is not working, and severe side effects do not mean that it is working.) This news was very disheartening, and we had to pick ourselves up and dust ourselves off to move on. Time for Plan B.

We then started CPT-11 plus Mitomycin. This time we were not so lucky on side effects. The very next day was hiccups day; day 4 was the start of severe diarrhea; day 8 was his "nadir" point ( lowest white blood cell count and he ended up in the hospital); and day 12 he started losing his hair. By day 19, we had to shave it off completely because there were just wisps left. His moustache and goatee are a part of his "signature," so he is hanging on to them even though they are quite thin. I love to touch and kiss his shaved head, but I can tell he is not comfortable with it, so I try to respect his space until he is more at ease with his new look.

Hand-and-foot syndrome

Hand-and-foot syndrome, known medically as palmar-plantar erythrodysesthesia or PPES, is a collection of symptoms of tingling, pain, soreness, loss of feeling, swelling, and skin peeling on the fingers and on the soles of the hands and feet. This is a common side effect following 5-FU therapy.

This syndrome usually recedes when fluorouracil therapy ends. Occasionally therapy is halted if the symptoms become very severe. Research has shown that PPES occurs more frequently when a continuous infusion pump is used to administer 5-fluorouracil.

One thing to watch out for that the doctors didn't tell me about was "hand-and-foot syndrome" or neurotoxicity. My hands and feet became very sensitive to any type of pressure. It was painful to walk, to open a jar or bottle. When I told the doctors about this, they became very concerned and lowered the dose of 5-fluorouracil that I was receiving in the continuous infusion pump.


Headache can be associated with administration of certain chemotherapy drugs used for colorectal cancer, such as irinotecan (CPT-11). Although headache usually is not considered serious, you should notify your doctor, particularly if pain is severe.

Heart damage

Call your doctor immediately if you experience any symptoms that resemble a heart attack, such as chest tightness or pain, difficulty in breathing, or numbness in the left arm or shoulder.

Fluorouracil, a drug used for colorectal cancer, can be cardiotoxic in certain vulnerable people when used in high doses.


Radiation therapy can exacerbate the painful symptoms associated with existing hemorrhoids. Common treatments for this condition include steroid foam, steroid suppositories, and sitz baths.

High blood pressure

Phone your doctor immediately if you notice rapid pulse, fluid retention, headache, or other symptoms of high blood pressure. High blood pressure can develop temporarily while one is receiving 5-fluorouracil.


If you have had radiation therapy to tissue in or near the rectum, or certain surgeries that remove either all of the colon or most of the rectum including anal muscles, you may experience temporary or permanent incontinence involving escape of fecal material or gas.

The solution to this problem depends on the cause. Ask your doctor what options are likely to help.

Indigestion (See Nausea)


If you have a fever of more than 1.5 degrees higher than your normal temperature, general malaise, severe chills, night sweats, burning or pain while urinating, headache, neck stiffness, coughing, or trouble breathing, phone your doctor without delay.

Infection can result when leukopenia, a lowering of white blood cell counts, occurs after treatment. The danger period for most patients is five to ten days after treatment. In general, chemotherapy is more likely to cause leukopenia than radiotherapy.

Preventive measures include hand-washing; avoiding scratches and cuts via gentle handling of the skin, such as using an electric razor and patting skin dry, rather than rubbing; thorough cooking of food; reducing human contact; and avoiding gardening and handling kitty litter.

If an infection develops, your doctor will examine you, and you may be admitted to the hospital, placed in an isolation room, and given a combination of immunoglobulin therapy, antibiotics, antiviral agents, or antifungal agents.

Insomnia (See Fatigue)

Jaundice (See Kidney damage and Liver or gallbladder dysfunction)

Kidney damage

Notify your doctor immediately if you have symptoms of kidney failure such as unusually high or low levels of urination, difficulty urinating, swollen limbs, yellowing skin, decreased sweat, or heart or circulatory symptoms.

Temporary or permanent damage to the kidneys may occur from tumor pressure against the ureters that drain the kidneys into the bladder, or with administration of certain drugs such as methotrexate.

Leg weakness

Following radical surgery for rectal cancer, unsteadiness, reduced strength, and numbness in the legs and feet may develop. It is thought that this is linked to surgeries that touch upon certain pelvic nerves. This side effect should diminish in about three months if physical therapy is diligently used.

Leukopenia (See Infection)

Liver or gallbladder dysfunction

Mild liver or gallbladder problems sometimes develop when you are fed only by IV line (TPN, total parenteral nutrition). These problems usually go away when you resume eating normally.

Scarring of the liver, called biliary sclerosis, can occur when an infusion pump delivers chemotherapy directly to the liver. Transient liver problems might result. Thus, if you are receiving chemotherapy directly to the liver (hepatic artery infusion or HAI) via pump, the side effects listed in the following paragraph are particularly germane. Some researchers believe that concurrent administration of corticosteroids such as prednisone can reduce scarring of the liver.

Because liver problems can be a sign of relapse, you should notify your doctor immediately if you notice any combination of symptoms of liver dysfunction: nausea, jaundice, swollen abdomen, pain in the upper abdomen, or mental confusion.

Mouth or rectal pain (stomatitis, mucositis)

Most people remember stories about vomiting when they think of chemotherapy, but treatments for colorectal cancer and other cancers actually may affect the entire gastrointestinal tract, from mouth to anus.

If you experience severe mouth sores, rectal pain that feels like hemorrhoids, or painful or bloody bowel movements, don't suffer in silence. Painkillers, suppositories, and perhaps IV feeding for about a week will help immensely. Some oncologists may prescribe a rinse called Magic Mouthwash that contains a painkiller, an antibiotic, and an antifungal.

Sucking on ice cubes or ice pops helps reduce or prevent the development of mouth sores and sore throat. I think that the idea is to cool the mouth down to reduce blood flow to the mouth area and thus reduce the amount of chemotherapy going to that area. In any event, it works. The suggestion is to start ten to fifteen minutes before treatment, continue during chemo and for about ten to fifteen minutes after. The down side is a keen aversion to ice pops! I cannot look at, or think about, that particular brand of ice pop without getting the shivers. Maybe it will pass with time.

Nail changes

Many colorectal cancer survivors report differences in the quality of fingernail and toenail growth during and after treatment. This problem is temporary, and will resolve on its own after treatment ends.

Nausea and vomiting

Phone your doctor immediately if nausea and vomiting are combined with any of the symptoms described previously under Infection.

Nausea and vomiting are the result of some, but not all, of the drugs and radiation treatments used for colorectal cancer treatment. Nausea associated with radiation therapy usually occurs only if the area just above the navel is irradiated. Nausea accompanying 5-fluorouracil administration is common.

It's important that nausea and vomiting are controlled, not just to reduce suffering, but to allow your body to absorb nutrients to heal, to keep you well hydrated and thus able to flush chemotherapy drugs from your body, to support your kidney function, and to allow for uninterrupted sleep during which the immune system is rebuilt. You should not suffer nobly through nausea and vomiting as a mark of strength: you may harm yourself if you do.

Fortunately, excellent drugs are available today to control nausea and vomiting. Zofran (ondansetron) and Kytril (granisetron) are two such anti-emetics, and anti-anxiety drugs such as Xanax, a drug similar to Valium, may work for brief episodes of nausea. Some steroids such as Decadron also work, for reasons that are unclear. Older, less effective drugs, such as Compazine, are also still in use, sometimes in combination with newer drugs.

Take your antinausea medications on time, even if you feel well. They work by priming your body before nausea sets in. Moreover, if you wait to take them until you feel bad, you may lose them as you vomit.

Keep your doctor informed about the success of these drugs, because they can be recombined and substituted by others until a good solution is found.

Some oncologists start by prescribing older, less expensive nausea drugs because their use is more acceptable to insurance companies--even though many patients report that drugs such as Zofran are more effective than other drugs. If your pharmaceutical insurance option is liberal, tell your doctor so that he will feel free to prescribe his best choice first.

Sometimes just the aroma of food can bring on nausea. If so, you might try eating foods that have been chilled.

If you are unable to keep food down in spite of nausea medication, feeding by IV line for a period of time will give your stomach a chance to recover.

Anticipatory nausea also is normal for many cancer patients. If you had treatment in the past that made you ill, during subsequent visits your central nervous system may react with nausea to visual cues or odors in the doctor's office before treatment is begun. You're not crazy: many people report this reaction, even years after treatment.

My husband took CPT-11 for seven months. He was on the four-weeks-on, two-weeks-off schedule. To help with side effects, we lengthened the infusion time from ninety minutes to two hours. In addition to the Decadron and Zofran which he took prior to the infusion, he often took Zofran every eight hours for several days after. Some people have their nausea controlled better with Kytril or Ativan rather than Zofran.

Neutropenia (See Infection)

Numbness and tingling

Peripheral neuropathy, which may include numbness, tingling, or pain in hands and feet, is sometimes seen after platinum-based therapy, such as oxaliplatin. Peripheral neuropathy associated with oxaliplatin is temporary; no treatment exists yet for this side effect.

Neuropathies of the pelvis may follow radiation therapy for rectal cancer, including pain, loss of sensation, or loss of bladder or anal control. These side effects are more pronounced when intraoperative radiotherapy (IORT) is used.

See also Hand-and-foot syndrome.


Pain can be caused by surgery, by drugs used for colorectal cancer, or by radiation therapy.

Postsurgical pain may persist for months or years following treatment. Although advanced surgical techniques are used to reduce pain, chiefly by avoiding nerve groups, the surgeon's primary concern is the curing of cancer by removing all diseased tissue. At times, healthy tissue must be sacrificed in order to achieve this goal. As a result, a variety of persistent painful phenomena might be experienced by colorectal cancer survivors, such as pelvic pain that spreads to other body parts, perineal pain, or phantom anus syndrome, a sensation of pain in nonexistent tissue after anal tissue has been removed.

Severe back pain may be associated with degenerative changes to the spine following radiation therapy targeted near the spine. Surgery to fuse spinal discs may alleviate this pain. Painful radiation fibrosis, a reaction of the immune system after exposure to radiation, can develop in any tissue that has been irradiated. Burning perineum syndrome, a sensation of burning pain in or near the scrotum, vagina, or near the anus, is known to occur in some colorectal cancer survivors treated with radiotherapy.

Pain in the hands and feet or abdominal cramps may arise during chemotherapy with 5-fluorouracil. See Abdominal pain and Hand-and-foot syndrome.

Pain during therapy that involves radiation implants may occur. Ask for pain medication immediately if the implants or the position you must hold cause pain. Report any unusual symptoms such as burning or sweating.

Many other examples could be listed, as pain is a symptom of many aberrant physical processes. The best treatment depends on a correct diagnosis. Consult your doctor or a pain management specialist to find the best treatment for your pain.

A discussion group for those suffering from cancer pain exists on the Internet. Visit to enroll in the Cancer-Pain discussion group.

Palmar-plantar erythrodysesthesia (See Hand-and-foot syndrome)


Pancytopenia is a lowering of all blood cells counts. It's treated with transfusions of red cells, platelets, or irradiated whole blood. See Infection for additional information.

Peripheral neuropathy (See Numbness and tingling)

Poor wound healing

Some treatment regimens call for chemotherapy, radiotherapy, or both before surgery in order to reduce the size of the tumor, thus enhancing the chance of a more successful surgical removal.

Both chemotherapy and radiotherapy can cause delays in wound healing by compromising the ability of healthy tissues to multiply and form scar tissue. Speak with your doctor as soon as possible if you suspect your healing is not progressing as it should.

Postsurgical confusion

Mild confusion to frank psychotic behavior occurs in some people following general anesthesia, especially in those over age 50. Although time is the best cure, a change in pain medication or room location might also help.

Pulmonary thrombosis (See Blood clots)

Radiation enteritis and proctitis (RASBI)

Radiotherapy targeted to the abdomen or pelvis can cause abdominal or rectal pain, diarrhea, bloody stools, or mucus in stools, also called radiation-associated small-bowel injury (RASBI). It may be a short-term effect that fades in four to eight weeks after treatment ends, or, in 5 to 15 percent of patients, it may become a long-term chronic problem.

Interference with the absorption of nutrients is one of the chief concerns. Enteritis is treated by controlling diarrhea with Kaopectate, Lomotil, Paregoric, Cholestyramine, Donnatal, Immodium, or narcotics. Steroid foam may be prescribed if the rectum is quite sore.

For some people, a change in diet might alleviate symptoms. Avoidance of lactose, fats, wheat gluten, and high carbohydrates reportedly help some colorectal cancer survivors with RASBI.

See also Abdominal pain and Diarrhea.

Recall sensitivities

Radiation therapy may damage tissue in a way that leaves it reactive to further treatment for months or years afterward. Radiation to an area can cause tissue in that area to react with pain and dysfunction when chemotherapy is administered afterward.

Rectal perforation

Radiotherapy for rectal cancer can weaken healthy tissue such that it may rupture. This is more often a late effect of radiotherapy, but may occur more quickly in certain people.

If you have unusual rectal or pelvic pain, fever, unusual odor of bowel movements, or passage of feces from the vagina, contact your doctor immediately.

Runny nose

Administration of the drug CPT-11 (irinotecan) can cause production of excess bodily fluids in some cases. Addition of atropine offsets these symptoms.

Sexual problems

A variety of problems with sexual performance and enjoyment can arise after surgery or radiotherapy for colorectal cancer.

A discussion group for those dealing with issues of sexuality following cancer treatment exists on the Internet. Visit to enroll in the Cancer-Sexuality discussion group.

Skin problems

A variety of skin problems--pain, burning, discoloration, scaling, wrinkling, dryness, rash, hives, redness, peeling, sun sensitivity--are associated with some treatments for colorectal cancer. Radiation therapy and certain chemotherapies used for colorectal cancers, such as fluorouracil and irinotecan (CPT-11), can cause skin problems.

Ask your doctor for help before tackling this on your own, because dermatology problems can be complex and hard to diagnose, and because certain skin symptoms, such as itching, may be a sign of an allergic response, or of serious changes such as relapse in the liver. Common remedies, such as lotions that contain alcohol, may make the problem worse, especially if itching is your chief complaint or if radiotherapy is still underway.

Sitz baths, baby wipes, and Balmex are good for symptoms that follow radiation therapy. I might add that I switched around to A&D ointment here and there. My radiation therapists told me to tell them about any side effects and were a great help. They gave me a purified aloe vera gel to use (don't get it over the counter).

The way I look at it is, some people will have greater problems than others. The main thing is speak up as soon as side effects show up, and the sooner relief will be attained!

Sore throat

For several drugs used against colorectal cancer, sore throat is a known side effect that is generally bothersome but not always serious. Contact your doctor so that she can determine whether this side effect is serious in your case, especially if sore throat is accompanied by other symptoms of allergic reaction or by fever.

Stomatitis (See Mouth or rectal pain)

Sun sensitivity (See Skin problems)


Administration of the drug CPT-11 (irinotecan) can cause profuse sweating in some cases. Addition of atropine offsets these symptoms.

Tumor lysis syndrome

The waste products of a tumor as it dies may disrupt natural levels of body substances such as electrolytes or antidiuretic hormone.

Tumor lysis syndrome, arising from the death of large tumors, may arise shortly after chemotherapy is started. Symptoms of kidney failure owing to excessive amounts of calcium, phosphate, and potassium being released by dying tumors are noteworthy, and can be offset with oral or IV hydration, careful monitoring of electrolytes, and use of diuretics.

If you or your loved ones notice any unusual symptoms, especially excessive thirst, unusually high or low levels of urination, swollen limbs, yellowing skin, decreased sweat, abdominal pain, or heart or circulatory symptoms, call the doctor.


Following radiation therapy, healthy skin that was in the path of the radiation beam might ulcerate. The condition might become chronic.

See Poor wound healing for more information.

Urinary problems

Radical pelvic surgery may affect urination by damaging tissue or nerves, or by causing adhesions--stringlike scar tissue--to develop and constrict the bladder or ureters.

Radiation therapy that cannot avoid the bladder may cause temporary or permanent changes in bladder function. The bladder may become less elastic, and the urge to urinate may become more frequent.

Urinary problems should be reported to your doctor promptly, as tumor pressure upon the bladder, or upon ureters that drain the kidneys into the bladder, also can cause urinary problems.

Water retention (See Urinary problems, Kidney damage, and Heart damage)

Weight loss

Most chemotherapies as well as radiotherapy for colorectal cancer cause rapidly dividing cells to die more frequently than other cells. As the cells lining the gastrointestinal tract are rapidly dividing cells, when these are exposed to anticancer drugs, they die sooner than their natural cycle would dictate. As a result, it may become difficult to absorb nutrients during treatment for colorectal cancer; the effect is made worse if nausea and diarrhea are present.

If you are losing weight during treatment, notify your doctor.

See the suggestions included under Appetite or taste changes, Diarrhea, and Nausea and vomiting.

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