Some chemotherapy drugs cause diarrhea. Others lead to constipation. These gastrointestinal side effects will go away when you finish treatment. In the meantime, there are things you can do to manage them.
For diarrhea, drink extra water and other clear liquids to stay hydrated, recommends the Leukemia & Lymphoma Society. Eat foods that are easy to digest, like skinless cooked vegetables, white bread, and bananas. Avoid things that make diarrhea worse, like dairy, high-fat foods, high-fiber foods, and spicy foods.
If constipation is the issue, add more fiber into your diet with whole-grain bread, oatmeal, fruits, vegetables, and beans. Drink extra fluids. Ask your doctor if you should take a fiber supplement, stool softener, or laxative to help move things along.