The digestive system includes the mouth; the tube through which food passes after being swallowed, called the esophagus; the stomach; the small intestine, where food is broken down and absorbed; the large intestine or colon, where unabsorbed material is stored for elimination; and the anus. The whole system, taken together, is responsible for digestion of food and elimination of waste. This section will discuss all parts of the digestive system except the mouth: the mouth, which is a common site of problems, has been given its own section.
HIV infection can affect any part of the digestive system, and does so commonly in the later stages. The symptoms are often a clue to which part of digestive system is being affected. Painful or difficult swallowing is usually a symptom of problems with the esophagus. Pain in the abdomen, nausea, and vomiting are usually symptoms of problems with the stomach. Diarrhea, pain, and malnutrition from the failure to absorb nutrients are all symptoms of problems with the small intestine. And pain, diarrhea, or constipation are symptoms of problems with the colon.
Many of the problems in the digestive system also interfere with nutrition. Anything that interferes with nutrition is especially important to someone with HIV infection, because HIV infection itself causes weight loss and nutritional deficiencies. Severe malnutrition also seems to further weaken the immune system. Anyone with HIV infection and such problems with the digestive system should be under the care of a physician.