Cancer : Bowel Obstruction, Diarrhea

by National Cancer Institute

(Page 3 of 4)

Bowel Obstruction

Description and Causes

A bowel obstruction may be caused by a narrowing of the intestine from inflammation or damage to the bowel, tumors, scar tissue, hernias, twisting of the bowel, or pressure on the bowel from outside the intestinal tract. It can also be caused by factors that interfere with the function of muscles, nerves, and blood flow to the bowel. Most bowel obstructions occur in the small intestine and are usually caused by scar tissue or hernias. The rest occur in the colon (large intestine) and are usually caused by tumors, twisting of the bowel, or diverticulitis. Symptoms will vary depending on whether the small or large intestine is involved.

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 abdominal surgery or radiation are at a higher risk of developing a bowel obstruction. Bowel obstructions are most common during the advanced stages of cancer. Assessment of Bowel Obstruction

The doctor will do a physical examination to find out whether the patient has abdominal pain, vomiting, or any movement of gas or stool in the bowel. Blood and urine tests may be done to detect any fluid and blood chemistry imbalances or infection. Abdominal x-rays and a barium enema may also be done to find the location of the bowel obstruction.

Treatment of Acute Bowel Obstruction

Patients who have abdominal symptoms that continue to become worse must be monitored frequently to prevent or detect early signs and symptoms of shock and constricting obstruction of the bowel. Medical treatment is necessary to prevent fluid and blood chemistry imbalances and shock.

A nasogastric tube may be inserted through the nose and esophagus into the stomach, or a colorectal tube may be inserted through the rectum into the colon to relieve pressure from a partial bowel obstruction. The nasogastric tube or colorectal tube may decrease swelling, remove fluid and gas build-up, or decrease the need for multiple surgical procedures; however, surgery may be necessary if the obstruction completely obstructs the bowel. Treatment of Chronic, Malignant Bowel Obstruction

Patients who have advanced cancer may have chronic, worsening bowel obstruction that cannot be removed with surgery. Sometimes, the doctor may be able to insert an expandable metal tube called a stent into the bowel to open the area that is blocked.

When neither surgery nor a stent placement is possible, the doctor may insert a gastrostomy tube through the wall of the abdomen directly into the stomach by a very simple procedure. The gastrostomy tube can relieve fluid and air build-up in the stomach and allow medications and liquids to be given directly into the stomach by pouring them down the tube. A drainage bag with a valve may also be attached to the gastrostomy tube. When the valve is open, the patient may be able to eat or drink by mouth without any discomfort because the food drains directly into the bag. This gives the patient the experience of tasting the food and keeping the mouth moist. Solid food should be avoided because it may block the tubing to the drainage bag.

If the patient's comfort is not improved with a stent or gastrostomy tube, and the patient cannot take anything by mouth, the doctor may prescribe injections or infusions of medications for pain and/or nausea and vomiting.

Diarrhea

Causes

In cancer patients, the most common cause of diarrhea is cancer treatment (chemotherapy, radiation therapy, bone marrow transplantation, or surgery). Other causes of diarrhea include antibiotic therapy, stress and anxiety related to being diagnosed with cancer and undergoing cancer treatment; and infection. Infection may be caused by viruses, bacteria, fungi, or other harmful microorganisms. Antibiotic therapy can cause inflammation of the lining of the bowel, resulting in diarrhea that often does not respond to treatment. Other causes of diarrhea in cancer patients include:

• The cancer itself.
• Physical reactions to diet.
• Medical problems and diseases other than cancer.
• The laxative regimen.
• Bowel impaction with leakage of stool around the blockage.

Undergoing surgery to the stomach and/or intestines can affect normal bowel function and cause diarrhea. Some chemotherapy drugs cause diarrhea by affecting how nutrients are broken down and absorbed in the small bowel. Radiation therapy to the abdomen and pelvis can cause inflammation of the bowel. Patients may have problems digesting food, and experience gas, bloating, cramping, and diarrhea. These symptoms may last up to 8 to 12 weeks after therapy or may not develop for months or years. Treatment may include diet changes, medications, or surgery. Patients who are undergoing radiation therapy while receiving chemotherapy often experience severe diarrhea. Hospitalization may not be required, since an outpatient clinic or special home care nursing may give the care and support needed. Each patient's symptoms should be evaluated to determine if intravenous fluids or special medication should be prescribed.

Patients who undergo donor bone marrow transplantation may develop graft-versus-host disease (GVHD). Stomach and intestinal symptoms of GVHD include nausea and vomiting, severe abdominal pain and cramping, and watery, green diarrhea. Symptoms may occur 1 week to 3 months after transplantation. Some patients may require long-term treatment and diet management.

Assessment

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

• 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?
• Have you been dizzy, extremely drowsy, or had any cramping, abdominal pain, nausea, vomiting, fever, or rectal bleeding?
• 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 medicine are you taking? How much and how often?
• Have you traveled recently?

The doctor will also do a physical examination that should include checking blood pressure, pulse, and respirations; evaluation of the skin and tissue lining the inside of the mouth to check for blood circulation and amount of fluid in the tissue; examination of the abdomen for pain, tenderness, and bowel sounds; and a rectal exam to check for stool impaction and collect stool to test for blood.

Stool may be tested in the laboratory to check for bacterial, fungal, or viral infections. Blood and urine tests may be done to detect fluid and blood chemistry imbalances or infection.

In some cases, abdominal x-rays may also be done to identify bowel obstruction or other abnormalities. In rare cases, a thorough examination of the rectum and colon may be done with a lighted tube inserted through the anus and into the colon.

Treatment

Diarrhea is treated by identifying and treating the problems causing diarrhea. For example, diarrhea may be caused by stool impaction and medications to prevent constipation. The doctor may make changes in medications, diet, and fluids. Diet changes that may help decrease diarrhea include eating small frequent meals and avoiding some of the following foods:

• Milk and dairy products.
• Spicy foods.
• Alcohol.
• Caffeine-containing foods and drinks.
• Some fruit juices.
• Gas-forming foods and drinks.
• High-fiber foods.
• High-fat foods.

For mild diarrhea, a diet of bananas, rice, apples, and toast (the BRAT diet) may decrease the frequency of stools. Patients should be encouraged to drink up to 3 quarts of clear fluids per day including water, sports drinks, broth, weak decaffeinated tea, caffeine-free soft drinks, clear juices, and gelatin. For severe diarrhea, the patient may need intravenous fluids or other forms of intravenous nutrition. (Refer to the PDQ summary on Nutrition in Cancer Care 1.)

To manage diarrhea caused by graft-versus-host disease (GVHD), the doctor may recommend a special 5-phase diet. During phase 1, the patient receives intravenous fluids and nothing by mouth to rest the bowel until the diarrhea slows down. In phase 2, the patient may begin drinking fluids. If the patient is able to drink fluids and the diarrhea improves, he or she may begin phase 3, eating solid foods that are low-fiber, low-fat, low-acid, and do not irritate the stomach. In phase 4, the patient is gradually allowed to eat regular foods. If the patient is able to eat regular foods without any episodes of diarrhea, he or she may begin phase 5, eating their regular diet. Many patients may continue to have problems digesting milk and dairy products.

Depending on the cause of the diarrhea, the doctor may change the laxative therapy regimen or may prescribe medications that slow down bowel activity, decrease bowel fluid secretions, and allow nutrients to be absorbed by the bowel.

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