Diarrhea
Diarrhea, frequent passage of abnormally loose, watery stool. Diarrhea usually develops suddenly and may last from several hours to a few days. It is often accompanied by abdominal pains, low fever, nausea, and vomiting. If the attacks are severe or increasingly frequent, exhaustion and dehydration can result. In normal digestion the large intestine absorbs excess water from liquid food residues produced by earlier phases of the digestive process before excreting semisolid stools. When the mucous membrane lining the large intestine is irritated or inflamed, food residues move through the large intestine too quickly and the resulting stool is watery because the large intestine cannot absorb the excess water. Diarrhea is not a disease. It is a symptom of numerous disorders, such as food poisoning from contaminated foods or beverages, infections by viruses and bacteria, or anxiety. Chronic diarrhea, which lasts weeks or months, may be caused by amoebic dysentery (intestinal infection), tu...