Burning diarrhea usually can be traced to one of two causes. In most cases, the burning comes from the enzymes and acids that break down food in the stomach and small intestine. Hot, spicy foods might also cause burning diarrhea.
During normal digestion, food is broken down by acid and enzymes in the stomach. This breakdown continues as the food passes into the small intestine, where nutrients and fluids are absorbed. By the time the food passes through the large intestine, the enzymes and acids have been neutralized, and all useful material has been drawn from the food, leaving only a dense lump of waste material, which passes from the body as a bowel movement. Depending on the food eaten, digestion might take anywhere from 12 to 24 hours.
Diarrhea speeds up this process, rushing food through the digestive tract. Intestines do not have sufficient time to draw out nutrients or water before passing from the body, usually with considerably urgency. The result is a watery or soupy bowel movement.
Enzymes and acid are introduced to the food in the stomach, where they begin to break down the food into a useful form, but they don’t have time to complete the task. These substances are still active when the bowel motion passes and can irritate the rectum. Burning diarrhea is most often caused by these digestive enzymes and stomach acid.
In some cases, spicy food might be responsible for burning diarrhea. Capsaicin, the active chemical found in most spicy foods, works by linking pain and heat sensations in the mouth. It also can irritate the digestive tract, triggering a bout of diarrhea. The capsaicin, when rushed through the body, doesn’t have time to break down and remains intact. When passed in the bowel movement, it causes the same heat and pain sensation, which is perceived as burning diarrhea.
A bout of burning diarrhea might have any of a number of causes. Bacterial infection from food poisoning is perhaps most common, but viral infection, reaction to food or medication and some intestinal disorders, such as irritable bowel syndrome, also might be responsible. In most cases, diarrhea is not a serous condition and can be easily treated at home.
Over-the-counter medication that can arrest these symptoms is available, but in many cases, patients are better off letting diarrhea run its course. Often, diarrhea is the body’s attempt to rid itself of some irritant, and preventing that removal will only prolong the condition. Medication should be a weapon of last resort unless directed by a doctor.
Instead, patients are urged to rehydrate with caffeine-free drinks to replace the fluids lost. Foods such as toast, yogurt, rice and bananas are recommended to ease symptoms. In cases where symptoms persist or where accompanied by other symptoms, such as fever, bloody or black stool or other worrying conditions, consultation with a doctor is recommended.