Cancer and Diarrhea
Cancer and Diarrhea
Diarrhea is defined as passing loose or watery stools three or more times within 24 hours, with or without accompanying discomfort. It occurs when water in the intestines is not adequately reabsorbed into the body for various reasons.
Common causes of diarrhea include anticancer treatments (such as certain immunotherapy drugs, targeted therapies, chemotherapy, or abdominal radiotherapy), non-cancer medications, infections, and surgical procedures. Other possible causes may include highly concentrated vitamin or mineral supplements, liquid nutritional supplements containing sugars or electrolytes, and tumor growth itself.
Some anticancer treatments may cause diarrhea that lasts for up to three weeks or longer.
What Patients Can Do
When diarrhea begins or you feel it may be starting, try low-residue, clear liquids such as water, weak tea, apple juice, peach or apricot nectar, clear broth, popsicles, or gelatin without solid additives. Avoid acidic beverages such as tomato juice, citrus juices, and carbonated soft drinks.
• Eat small, frequent meals instead of large ones.
• Avoid greasy or spicy foods, as well as foods that are very hot; avoid bran, raw fruits and vegetables, and caffeine.
• Do not drink alcohol or smoke.
• If milk or dairy products seem to worsen your diarrhea, try to avoid them.
• Include foods rich in potassium (such as bananas, potatoes, apricots, and sports drinks like Gatorade). Potassium is an important mineral that can be lost through diarrhea.
• Keep a record of your bowel movements, including frequency, volume, and any possible triggers.
• After each bowel movement, gently clean the anal area with mild soap and water, then rinse and pat dry. Baby wipes may also be used.
• Apply a protective ointment (such as petroleum jelly) to the anal area to prevent irritation.
• Warm sitz baths can help relieve anal discomfort.
• Take antidiarrheal medications only as prescribed by your doctor.
• As diarrhea begins to improve, gradually introduce easily digestible foods such as rice, bananas, applesauce, yogurt, mashed potatoes, low-fat cheese, and dry toast. If symptoms continue to improve after 1–2 days, you may slowly return to your regular diet.
What Caregivers Can Do
• Encourage the patient to drink about 3 liters of fluids per day (as tolerated).
• Record bowel movement details to help determine when medical attention is needed.
• Consult the oncology care team before giving any over-the-counter antidiarrheal medications.
• Check the anal area for redness, peeling, or skin breakdown.
• Place absorbent pads or plastic sheets under the patient to protect bedding or furniture from soiling.
Contact Your Oncology Care Team or Seek Medical Attention If:
• You have six or more episodes of loose stool within 24 hours, without improvement after two days.
• There is blood around the anus or blood in the stool.
• You develop new abdominal cramps lasting two or more days.
• You have no urination for over 12 hours.
• You have not consumed any fluids for over 24 hours.
• Your oral temperature exceeds 38°C (100.4°F).
• You experience abdominal swelling or bloating.
• You have had constipation for several days, followed by a sudden onset of small amounts of diarrhea or liquid stool leakage, which may indicate fecal impaction.
