Diarrhea

Diarrhea can be one of the most disturbing side effects of cancer. It tends to be under-recognized in cancer populations; however, 50%-80% of people receiving cancer treatments will experience diarrhea.

Diarrhea is the result of a condition called mucositis-a treatment-induced inflammation that can affect the entire digestive tract. (For more information about mucositis, see "Throat Irritation.") Diarrhea can cause fatigue, weight loss, and other conditions that could complicate your treatment regimen.

Having diarrhea during or after treatments is more than a nuisance. It can affect your quality of life and can reduce the maximal dose of chemotherapy or radiation that can be given to you safely. In extreme situations, diarrhea can be life-threatening.

Do I really have diarrhea?

That’s an important question. The answer depends on what type of cancer you have, whether you have an ostomy, and what your symptoms are today as compared to a baseline—for example, your bowel habits before you had surgery or before you started a chemotherapy or radiation series. This is one reason why your oncology nurse or physician evaluates you before each treatment—and why you should be forthcoming about your symptoms, even if you feel squeamish talking about them. (Healthcare professionals use National Cancer Institute criteria for determining diarrhea and its severity compared to baseline. For more information, visit NCI’s Web site.)

Note. Based on information from Saltz, L.B. (2003). Understanding and managing chemotherapy-induced diarrhea. Journal of Supportive Oncology, 1(1), 35–46.

Don't self-medicate

You may think diarrhea is something you can remedy simply by taking an over-the-counter medication. However, diarrhea in cancer patients is more complicated than that. The treatment that will help the most depends on the type of cancer you have and whether the diarrhea is a result of chemotherapy or radiation treatments.