Ailments of the Digestive System
Infection of or damage to any part of the digestive system may affect digestion as well as other bodily functions. Common infectious agents that attack digestive organs include the mumps virus, which often infects the salivary glands; the bacterium Helicobacter pylori, which causes most stomach and duodenal ulcers ; and viruses and bacteria that cause various forms of gastroenteritis, often called stomach flu or traveler’s diarrhea. Appendicitis is an inflammation of the appendix , a tube-like pouch about 9 cm (3.5 in) long that branches off the large intestine. It occurs most commonly among children and young adults. Diarrhea —frequent elimination of loose, watery feces—is a symptom of many disorders that occurs when the large intestine is irritated or inflamed. As a result, food residues move through it too quickly for it to absorb the excess water. The opposite condition, constipation, occurs when the large intestine absorbs too much water because food residues are moving slowly.