Gastrointestinal Complications (PDQ®)

With constipation, bowel movements are difficult or don’t happen as often as usual.

Constipation is the slow movement of stool through the large intestine. The longer it takes for the stool to move through the large intestine, the more it loses fluid and the drier and harder it becomes. The patient may be unable to have a bowel movement, have to push harder to have a bowel movement, or have fewer than their usual number of bowel movements.

Certain medicines, changes in diet, not drinking enough fluids, and being less active are common causes of constipation.

Constipation is a common problem for cancer patients. Cancer patients may become constipated by any of the usual factors that cause constipation in healthy people. These include older age, changes in diet and fluid intake, and not getting enough exercise. In addition to these common causes of constipation, there are other causes in cancer patients.

Other causes of constipation include:

• Medicines

  • Opioids and other pain medicines. This is one of the main causes of constipation in cancer patients.
  • Chemotherapy.
  • Medicines for anxiety and depression.
  • Antacids.
  • Diuretics (drugs that increase the amount of urine made by the body).
  • Supplements such as iron and calcium.
  • Sleep medicines.
  • Drugs used for anesthesia (to cause loss of feeling for surgery or other procedures).
• Diet

  • Not drinking enough water or other fluids. This is a common problem for cancer patients.
  • Not eating enough food, especially high-fiber food.
• Bowel movement habits

  • Not going to the bathroom when the need for a bowel movement is felt.
  • Using laxatives and/or enemas too often.
• Conditions that prevent activity and exercise

  • Spinal cord injury or pressure on the spinal cord from a tumor or other cause.
  • Broken bones.
  • Fatigue.
  • Weakness.
  • Long periods of bed rest or not being active.
  • Heart problems.
  • Breathing problems.
  • Anxiety.
  • Depression.
• Intestinal disorders

  • Irritable colon.
  • Diverticulitis (inflammation of small pouches in the colon called diverticula).
  • Tumor in the intestine.
• Muscle and nerve disorders

  • Brain tumors.
  • Spinal cord injury or pressure on the spinal cord from a tumor or other cause.
  • Paralysis (loss of ability to move) of both legs.
  • Stroke or other disorders that cause paralysis of part of the body.
  • Peripheral neuropathy (pain, numbness, tingling) of feet.
  • Weakness of the diaphragm (the breathing muscle below the lungs) or abdominal muscles. This makes it hard to push to have a bowel movement.
• Changes in body metabolism

  • Having a low level of thyroid hormone, potassium, or sodium in the blood.
  • Having too much nitrogen or calcium in the blood.
• Environment

  • Having to go farther to get to a bathroom.
  • Needing help to go to the bathroom.
  • Being in unfamiliar places.
  • Having little or no privacy.
  • Feeling rushed.
  • Living in extreme heat that causes dehydration.
  • Needing to use a bedpan or bedside commode.
• Narrow colon

  • Scars from radiation therapy or surgery.
  • Pressure from a growing tumor.

An assessment is done to help plan treatment.

The assessment includes a physical exam and questions about the patient's usual bowel movements and how they have changed.

The following tests and procedures may be done to help find the cause of the constipation:

• Physical exam: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. The doctor will check for bowel sounds and swollen, painful abdomen.
• Digital rectal exam (DRE): An exam of the rectum. The doctor or nurse inserts a lubricated, gloved finger into the lower part of the rectum to feel for lumps or anything else that seems unusual. In women, the vagina may also be examined.
• Fecal occult blood test: A test to check stool for blood that can only be seen with a microscope. Small samples of stool are placed on special cards and returned to the doctor or laboratory for testing.

  

  A guaiac fecal occult blood test (FOBT) checks for occult (hidden) blood in the stool. Small samples of stool are placed on a special card and returned to a doctor or laboratory for testing.

• Proctoscopy: An exam of the rectum using a proctoscope, inserted into the rectum. A proctoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue to be checked under a microscope for signs of disease.
• Colonoscopy: A procedure to look inside the rectum and colon for polyps, abnormal areas, or cancer. A colonoscope is inserted through the rectum into the colon. A colonoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer.

  

  Colonoscopy. A thin, lighted tube is inserted through the anus and rectum and into the colon to look for abnormal areas.

• Abdominal x-ray: An x-ray of the organs inside the abdomen. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.

There is no “normal” number of bowel movements for a cancer patient. Each person is different. You will be asked about bowel routines, food, and medicines:

• How often do you have a bowel movement? When and how much?
• When was your last bowel movement? What was it like (how much, hard or soft, color)?
• Was there any blood in your stool?
• Has your stomach hurt or have you had any cramps, nausea, vomiting, gas, or feeling of fullness near the rectum?
• Do you use laxatives or enemas regularly?
• What do you usually do to relieve constipation? Does this usually work?
• What kind of food do you eat?
• How much and what type of fluids do you drink each day?
• What medicines are you taking? How much and how often?
• Is this constipation a recent change in your normal habits?
• How many times a day do you pass gas?

For patients who have colostomies, care of the colostomy will be discussed.

Treating constipation is important to make the patient comfortable and to prevent more serious problems.

It's easier to prevent constipation than to relieve it. The health care team will work with the patient to prevent constipation. Patients who take opioids may need to start taking laxatives right away to prevent constipation.

Constipation can be very uncomfortable and cause distress. If left untreated, constipation may lead to fecal impaction. This is a serious condition in which stool will not pass out of the colon or rectum. It's important to treat constipation to prevent fecal impaction.

Prevention and treatment are not the same for every patient. Do the following to prevent and treat constipation:

• Keep a record of all bowel movements.
• Drink eight 8-ounce glasses of fluid each day. Patients who have certain conditions, such as kidney or heart disease, may need to drink less.
• Get regular exercise. Patients who cannot walk may do abdominal exercises in bed or move from the bed to a chair.
• Increase the amount of fiber in the diet by eating more of the following:

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  Fruits, such as raisins, prunes, peaches, and apples.

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  Vegetables, such as squash, broccoli, carrots, and celery.

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  Whole grain cereals, whole grain breads, and bran.

  It's important to drink more fluids when eating more high-fiber foods, to avoid making constipation worse. Patients who have had a small or large intestinal obstruction or have had intestinal surgery (for example, a colostomy) should not eat a high-fiber diet.
• Drink a warm or hot drink about one half-hour before the usual time for a bowel movement.
• Find privacy and quiet when it is time for a bowel movement.
• Use the toilet or a bedside commode instead of a bedpan.
• Take only medicines that are prescribed by the doctor. Medicines for constipation may include bulking agents, laxatives, stool softeners, and drugs that cause the intestine to empty.
• Use suppositories or enemas only if ordered by the doctor. In some cancer patients, these treatments may lead to bleeding, infection, or other harmful side effects.

When constipation is caused by opioids, treatment may be drugs that stop the effects of the opioids or other medicines, stool softeners, enemas, and/or manual removal of stool.

Fecal impaction is a mass of dry, hard stool that will not pass out of the colon or rectum.

Fecal impaction is dry stool that cannot pass out of the body. Patients with fecal impaction may not have gastrointestinal (GI) symptoms. Instead, they may have problems with circulation, the heart, or breathing. If fecal impaction is not treated, it can get worse and cause death.

A common cause of fecal impaction is using laxatives too often.

Repeated use of laxatives in higher and higher doses makes the colon less able to respond naturally to the need to have a bowel movement. This is a common reason for fecal impaction. Other causes include:

• Opioid pain medicines.
• Little or no activity over a long period.
• Diet changes.
• Constipation that is not treated. See the section above on causes of constipation.

Certain types of mental illness may lead to fecal impaction.

Symptoms of fecal impaction include being unable to have a bowel movement and pain in the abdomen or back.

The following may be symptoms of fecal impaction:

• Being unable to have a bowel movement.
• Having to push harder to have a bowel movement of small amounts of hard, dry stool.
• Having fewer than the usual number of bowel movements.
• Having pain in the back or abdomen.
• Urinating more or less often than usual, or being unable to urinate.
• Breathing problems, rapid heartbeat, dizziness, low blood pressure, and swollen abdomen.
• Having sudden, explosive diarrhea (as stool moves around the impaction).
• Leaking stool when coughing.
• Nausea and vomiting.
• Dehydration.
• Being confused and losing a sense of time and place, with rapid heartbeat, sweating, fever, and high or low blood pressure.

These symptoms should be reported to the health care provider.

Assessment includes a physical exam and questions like those asked in the assessment of constipation.

The doctor will ask questions similar to those for the assessment of constipation:

• How often do you have a bowel movement? When and how much?
• When was your last bowel movement? What was it like (how much, hard or soft, color)?
• Was there any blood in your stool?
• Has your stomach hurt or have you had any cramps, nausea, vomiting, gas, or feeling of fullness near the rectum?
• Do you use laxatives or enemas regularly?
• What do you usually do to relieve constipation? Does this usually work?
• What kind of food do you eat?
• How much and what type of fluids do you drink each day?
• What medicines are you taking? How much and how often?
• Is this constipation a recent change in your normal habits?
• How many times a day do you pass gas?

The doctor will do a physical exam to find out if the patient has a fecal impaction. The following tests and procedures may be done:

• Physical exam: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual.
• X-rays: An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body. To check for fecal impaction, x-rays of the abdomen or chest may be done.
• Digital rectal exam (DRE): An exam of the rectum. The doctor or nurse inserts a lubricated, gloved finger into the lower part of the rectum to feel for a fecal impaction, lumps, or anything else that seems unusual.
• Sigmoidoscopy: A procedure to look inside the rectum and sigmoid (lower) colon for a fecal impaction, polyps, abnormal areas, or cancer. A sigmoidoscope is inserted through the rectum into the sigmoid colon. A sigmoidoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer.

  

  Sigmoidoscopy. A thin, lighted tube is inserted through the anus and rectum and into the lower part of the colon to look for abnormal areas.

• Blood tests: Tests done on a sample of blood to measure the amount of certain substances in the blood or to count different types of blood cells. Blood tests may be done to look for signs of disease or agents that cause disease, to check for antibodies or tumor markers, or to see how well treatments are working.
• Electrocardiogram (EKG): A test that shows the activity of the heart. Small electrodes are placed on the skin of the chest, wrists, and ankles and are attached to an electrocardiograph. The electrocardiograph makes a line graph that shows changes in the electrical activity of the heart over time. The graph can show abnormal conditions, such as blocked arteries, changes in electrolytes (particles with electrical charges), and changes in the way electrical currents pass through the heart tissue.

A fecal impaction is usually treated with an enema.

The main treatment for impaction is to moisten and soften the stool so it can be removed or passed out of the body. This is usually done with an enema. Enemas are given only as prescribed by the doctor since too many enemas can damage the intestine. Stool softeners or glycerin suppositories may be given to make the stool softer and easier to pass. Some patients may need to have stool manually removed from the rectum after it is softened.

Laxatives that cause the stool to move are not used because they can also damage the intestine.

A bowel obstruction is a blockage of the small or large intestine by something other than fecal impaction.

Bowel obstructions (blockages) keep the stool from moving through the small or large intestines. They may be caused by a physical change or by conditions that stop the intestinal muscles from moving normally. The intestine may be partly or completely blocked. Most obstructions occur in the small intestine.

Physical changes

• The intestine may become twisted or form a loop, closing it off and trapping stool.
• Inflammation, scar tissue from surgery, and hernias can make the intestine too narrow.
• Tumors growing inside or outside the intestine can cause it to be partly or completely blocked.

If the intestine is blocked by physical causes, it may decrease blood flow to blocked parts. Blood flow needs to be corrected or the affected tissue may die.

Conditions that affect the intestinal muscle

• Paralysis (loss of ability to move).
• Blocked blood vessels going to the intestine.
• Too little potassium in the blood.

The most common cancers that cause bowel obstructions are cancers of the colon, stomach, and ovary.

Other cancers, such as lung and breast cancers and melanoma, can spread to the abdomen and cause bowel obstruction. Patients who have had surgery on the abdomen or radiation therapy to the abdomen have a higher risk of a bowel obstruction. Bowel obstructions are most common during the advanced stages of cancer.

Assessment includes a physical exam and imaging tests.

The following tests and procedures may be done to diagnose a bowel obstruction:

• Physical exam: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. The doctor will check to see if the patient has abdominal pain, vomiting, or any movement of gas or stool in the bowel.
• Complete blood count (CBC): A procedure in which a sample of blood is drawn and checked for the following:

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  The number of red blood cells, white blood cells, and platelets.

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  The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.

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  The portion of the blood sample made up of red blood cells.

• Electrolyte panel: A blood test that measures the levels of electrolytes, such as sodium, potassium, and chloride.
• Urinalysis: A test to check the color of urine and its contents, such as sugar, protein, red blood cells, and white blood cells.
• Abdominal x-ray: An x-ray of the organs inside the abdomen. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
• Barium enema: A series of x-rays of the lower gastrointestinal tract. A liquid that contains barium (a silver-white metallic compound) is put into the rectum. The barium coats the lower gastrointestinal tract and x-rays are taken. This procedure is also called a lower GI series. This test may show what part of the intestine is blocked.

  

  Barium enema procedure. The patient lies on an x-ray table. Barium liquid is put into the rectum and flows through the colon. X-rays are taken to look for abnormal areas.

Treatment is different for acute and chronic bowel obstructions.

Diarrhea is frequent, loose, and watery bowel movements.

Diarrhea is frequent, loose, and watery bowel movements. Acute diarrhea lasts more than 4 days but less than 2 weeks. Symptoms of acute diarrhea may be loose stools and passing more than 3 unformed stools in one day. Diarrhea is chronic (long-term) when it goes on for longer than 2 months.

Diarrhea can occur at any time during cancer treatment. It can be physically and emotionally stressful for patients who have cancer.

In cancer patients, the most common cause of diarrhea is cancer treatment.

Causes of diarrhea in cancer patients include the following:

• Cancer treatments, such as chemotherapy, targeted therapy, radiation therapy, bone marrow transplant, and surgery.

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  Some chemotherapy and targeted therapy drugs cause diarrhea by changing how nutrients are broken down and absorbed in the small intestine. More than half of patients who receive chemotherapy have diarrhea that needs to be treated.

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  Radiation therapy to the abdomen and pelvis can cause inflammation of the bowel. Patients may have problems digesting food, and have gas, bloating, cramps, and diarrhea. These symptoms may last up to 8 to 12 weeks after treatment or may not happen for months or years. Treatment may include diet changes, medicines, or surgery.

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  Patients who are having radiation therapy and chemotherapy often have severe diarrhea. Hospital treatment may not be needed. Treatment may be given at an outpatient clinic or with home care. Intravenous (IV) fluids may be given or medicines may be prescribed.

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  Patients who have a donor bone marrow transplant may develop graft-versus-host disease (GVHD). Stomach and intestinal symptoms of GVHD include nausea and vomiting, severe abdominal pain and cramps, and watery, green diarrhea. Symptoms may show up 1 week to 3 months after the transplant.

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  Surgery on the stomach or intestines.

• The cancer itself.
• Stress and anxiety from being diagnosed with cancer and having cancer treatment.
• Medical conditions and diseases other than cancer.
• Infections.
• Antibiotic therapy for certain infections. Antibiotic therapy can irritate the lining of the bowel and cause diarrhea that often does not get better with treatment.
• Laxatives.
• Fecal impaction in which the stool leaks around the blockage.
• Certain foods that are high in fiber or fat.

Assessment includes a physical exam, lab tests, and questions about diet and bowel movements.

Because diarrhea can be life-threatening, it is important to find out the cause so treatment can begin as soon as possible. The doctor may ask the following questions to help plan treatment:

• How often have you had bowel movements in the past 24 hours?
• When was your last bowel movement? What was it like (how much, how hard or soft, what color)? Was there any blood?
• Was there any blood in your stool or any rectal bleeding?
• Have you been dizzy, very drowsy, or had any cramps, pain, nausea, vomiting, or fever?
• What have you eaten? What and how much have you had to drink in the past 24 hours?
• Have you lost weight recently? How much?
• How often have you urinated in the past 24 hours?
• What medicines are you taking? How much and how often?
• Have you traveled recently?

Tests and procedures may include the following:

• Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken. The exam will include checking blood pressure, pulse, and breathing; checking for dryness of the skin and tissue lining the inside of the mouth; and checking for abdominal pain and bowel sounds.
• Digital rectal exam (DRE): An exam of the rectum. The doctor or nurse inserts a lubricated, gloved finger into the lower part of the rectum to feel for lumps or anything else that seems unusual. The exam will check for signs of fecal impaction. Stool may be collected for laboratory tests.
• Fecal occult blood test: A test to check stool for blood that can only be seen with a microscope. Small samples of stool are placed on special cards and returned to the doctor or laboratory for testing.
• Stool tests: Laboratory tests to check the water and sodium levels in stool, and to find substances that may be causing diarrhea. Stool is also checked for bacterial, fungal, or viral infections.
• Complete blood count (CBC): A procedure in which a sample of blood is drawn and checked for the following:

  -

  The number of red blood cells, white blood cells, and platelets.

  -

  The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.

  -

  The portion of the blood sample made up of red blood cells.

• Electrolyte panel: A blood test that measures the levels of electrolytes, such as sodium, potassium, and chloride.
• Urinalysis: A test to check the color of urine and its contents, such as sugar, protein, red blood cells, and white blood cells.
• Abdominal x-ray: An x-ray of the organs inside the abdomen. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body. Abdominal x-rays may also be done to look for a bowel obstruction or other problems.

Treatment of diarrhea depends on what is causing it.

Treatment depends on the cause of the diarrhea. The doctor may make changes in medicines, diet, and/or fluids.

• A change in the use of laxatives may be needed.
• Medicine to treat diarrhea may be prescribed to slow down the intestines, decrease fluid secreted by the intestines, and help nutrients be absorbed.
• Diarrhea caused by cancer treatment may be treated by changes in diet. Eat small frequent meals and avoid the following foods:

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  Milk and dairy products.

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  Spicy foods.

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  Alcohol.

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  Foods and drinks that have caffeine.

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  Certain fruit juices.

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  Foods and drinks that cause gas.

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  Foods high in fiber or fat.

• A diet of bananas, rice, apples, and toast (the BRAT diet) may help mild diarrhea.
• Drinking more clear liquids may help decrease diarrhea. It is best to drink up to 3 quarts of clear fluids a day. These include water, sports drinks, broth, weak decaffeinated tea, caffeine-free soft drinks, clear juices, and gelatin. For severe diarrhea, the patient may need intravenous (IV) fluids or other forms of IV nutrition.
• Diarrhea caused by graft-versus-host-disease (GVHD) is often treated with a special diet. Some patients may need long-term treatment and diet management.
• Probiotics may be recommended. Probiotics are live microorganisms used as a dietary supplement to help with digestion and normal bowel function. A bacterium found in yogurt called Lactobacillus acidophilus, is the most common probiotic.
• Patients who have diarrhea with other symptoms may need fluids and medicine given by IV.

Radiation enteritis is inflammation of the intestine caused by radiation therapy.

Radiation enteritis is a condition in which the lining of the intestine becomes swollen and inflamed during or after radiation therapy to the abdomen, pelvis, or rectum. The small and large intestine are very sensitive to radiation. The larger the dose of radiation, the more damage may be done to normal tissue. Most tumors in the abdomen and pelvis need large doses of radiation. Almost all patients receiving radiation to the abdomen, pelvis, or rectum will have enteritis.

Doctors are studying whether the order that radiation therapy, chemotherapy, and surgery are given affects how severe the enteritis will be.

Symptoms may begin during radiation therapy or months to years later.

Radiation enteritis may be acute or chronic:

• Acute radiation enteritis occurs during radiation therapy and may last up to 8 to 12 weeks after treatment stops.
• Chronic radiation enteritis may appear months to years after radiation therapy ends, or it may begin as acute enteritis and keep coming back.

The total dose of radiation and other factors affect the risk of radiation enteritis.

Only 5% to 15% of patients treated with radiation to the abdomen will have chronic problems. The amount of time the enteritis lasts and how severe it is depend on the following:

• The total dose of radiation received.
• The amount of normal intestine treated.
• The tumor size and how much it has spread.
• If chemotherapy was given at the same time as the radiation therapy.
• If radiation implants were used.
• If the patient has high blood pressure, diabetes, pelvic inflammatory disease, or poor nutrition.
• If the patient has had surgery to the abdomen or pelvis.

Acute and chronic enteritis have symptoms that are a lot alike.

Patients with acute enteritis may have the following symptoms:

• Nausea.
• Vomiting.
• Abdominal cramps.
• Frequent urges to have a bowel movement.
• Rectal pain, bleeding, or mucus in the stool.
• Watery diarrhea.
• Feeling very tired.

Symptoms of acute enteritis usually go away 2 to 3 weeks after treatment ends.

Symptoms of chronic enteritis usually appear 6 to 18 months after radiation therapy ends. It can be hard to diagnose. The doctor will first check to see if the symptoms are being caused by a recurrent tumor in the small intestine. The doctor will also need to know the patient's full history of radiation treatments.

Patients with chronic enteritis may have the following signs and symptoms:

• Abdominal cramps.
• Bloody diarrhea.
• Frequent urges to have a bowel movement.
• Greasy and fatty stools.
• Weight loss.
• Nausea.

Assessment of radiation enteritis includes a physical exam and questions for the patient.

Patients will be given a physical exam and be asked questions about the following:

• Usual pattern of bowel movements.
• Pattern of diarrhea:

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  When it started.

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  How long it has lasted.

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  How often it occurs.

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  Amount and type of stools.

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  Other symptoms with the diarrhea (such as gas, cramping, bloating, urgency, bleeding, and rectal soreness).

• Nutrition health:

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  Height and weight.

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  Usual eating habits.

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  Changes in eating habits.

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  Amount of fiber in the diet.

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  Signs of dehydration (such as poor skin tone, increased weakness, or feeling very tired).

• Stress levels and ability to cope.
• Changes in lifestyle caused by the enteritis.

Treatment depends on whether the radiation enteritis is acute or chronic.

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This PDQ cancer information summary has current information about the causes and treatment of gastrointestinal complications, including constipation, impaction, bowel obstruction, diarrhea, and radiation enteritis. It is meant to inform and help patients, families, and caregivers. It does not give formal guidelines or recommendations for making decisions about health care.

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PDQ® Supportive and Palliative Care Editorial Board. PDQ Gastrointestinal Complications. Bethesda, MD: National Cancer Institute. Updated <MM/DD/YYYY>. Available at: https://www.cancer.gov/about-cancer/treatment/side-effects/constipation/GI-complications-pdq. Accessed <MM/DD/YYYY>. [PMID: 26389438]

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