Chemotherapy induced diarrhea can happen due to the cancer itself, as a side effect of the chemotherapy drug, surgery of the bowel or colon, lowered immunity that makes you susceptible to infections or due to other reasons like stress, anxiety, antibiotics, radiation, etc. Cancer chemotherapy drugs  sometimes give side effects. It causes anal skin irritation, stomach pain, cramping and loss of appetite. Chemotherapy drugs affecting the lining of the intestine cause chemotherapy-induced diarrhea. A few chemotherapy drugs give side effect and managing side effects of chemotherapy  is a bit difficult.
Diarrhea could be defined as loose, watery stools occurring frequently in a day. It is not an occasional loose motion or frequent passing of normal stools.

Diarrhea causes dehydration, as you tend to lose all the water and nutrients in the body. If diarrhea continues even after taking medications, fluids and water are given intravenously on an outpatient basis. It is extremely important to keep yourself hydrated during chemotherapy and otherwise.

Certain Cancers Causing Diarrhea -

• Hormone-producing tumors like carcinoid syndrome and Zollinger-Ellison syndrome
• Colon cancer
• Lymphoma
• Medullary carcinoma of the thyroid
• Pancreatic cancer
• Stomach tumor

Chemotherapy Drugs Causing Diarrhea

There are different types of chemotherapy drugs  but only certain chemotherapy drugs cause side effects.

• Drugs like irinotecan and bolus 5-fluorouracil used to treat colorectal cancer cause diarrhea.
• Drugs like methotrexate, docetaxel, doxorubicin and dactinomycin also cause diarrhea.
• This side effect depends a lot on the dose and frequency of the drug used and if it suits the patient well.

Antibiotics, Medications and Other Factors Causing Diarrhea

• Drugs like cephalosporin, clindamycin, erythromycin, penicillin, quinolones, and tetracycline cause diarrhea.
• Certain antacids containing magnesium cause diarrhea.
• Certain intestinal bacteria also tend to cause diarrhea.
• Certain food allergies, lactose intolerance, etc cause diarrhea.

Medications for Diarrhea

• It is best to consult your doctor before taking any medicines, even OTC medications.
• There are several OTC medications for diarrhea, like Pepto-Bismol, Imodium, and Maalox.
• A very common prescription drug used to treat diarrhea is diphenoxylate that is commercially known as Lomotil.

Managing Chemotherapy Diarrhea

• Drink plenty of fluids to replace the lost fluid contents. You can drink water, ginger ale, clear soups and liquids, decaffeinated tea, etc.
• Avoid aerated drinks, caffeine and alcohol.
• Drink slowly and make sure the drinks are at room temperature.
• Eat small portions of food 5-6 times in the day instead of three large meals.
• Eat bananas, oranges, potatoes, peaches and apricots, which are good sources of potassium.
• A clear liquid diet gives rest to your digestive system. However, do not be on a liquid diet for more than 5 days, as this does not have all the nutrients our body requires.
• Eat low-fiber foods like white bread, white rice or noodles, creamed cereals, ripe bananas, canned or cooked fruit without the skin, cottage cheese, mashed or baked potatoes without the skin, pureed vegetables, etc
• Avoid high-fiber foods that cause diarrhea like whole grain breads, wheat bread, cereals, raw vegetables, beans, nuts, seeds, popcorn and fresh fruits.
• Avoid fatty foods, sweets, milk and milk products.

Chemotherapy diarrhea should be treated at the earliest as it can hamper the quality of life and at times could be fatal. It causes a lot of fatigue and weakness due to loss of fluids. Fortunately, there are enough medication and home remedies to control it.