Enteritis is the inflammation of small intestine caused by the drinking of contaminated water with bacteria and viruses. Mild cases of enteritis generally clear up within a few days. They do not require medical treatment. People with diarrhea must replenish their fluids. If you cannot get enough fluids, your doctor may recommend rehydration with electrolyte solutions. These solutions are made up of primarily water and the essential electrolytes: sodium (salt) and potassium. In acute cases, intravenous fluids, medications, or hospitalization may be necessary. In patients with chronic radiation enteritis, changes to radiation therapy may be required. You may even need to stop radiation entirely. In some cases, it may be necessary to have surgery performed to cut out (dissect) the part of the bowel that has been damaged.