Diarrhea is an increase in the water content, frequency, and volume of a person's bowel movements.
Diarrhea is frequent in people with HIV disease. Diarrhea can be a serious problem. Mild cases of diarrhea disappear within a few days. Severe diarrhea, however, can cause serious dehydration or nutritional problems. Bacteria, parasites, fungi, or viruses can cause the infection.