Delayed radiation enteritis is a chronic disease which has a complex pathogenesis involving changes in the majority of the intestinal wall. Diagnosis
Diagnosis may be simple in cases where the patients signs and symptoms are idiopathic to a specific cause. However, this is generally not the case, considering that many pathogens which cause enteritis may exhibit similar symptoms, especially early in the disease. In particular, campylobacter, shigella, salmonella and many other bacteria induce acute self-limited colitis, an inflammation of the lining of the colon which appears similar under the microscope.A medical history, physical examination and tests such as blood counts, stool cultures, CT scans, MRIs, PCRs, colonoscopies and upper endoscopies may be used in order to perform a differential diagnosis. A biopsy may be required to obtain a sample for histopathology. Treatment
Mild cases usually do not require treatment and will go away after a few days in healthy people. In cases where symptoms persist or when it is more severe, specific treatments based on the initial cause may be required.In cases where diarrhea is present, replenishing fluids lost is recommended, and in cases with prolonged or severe diarrhoea which persists, intravenous rehydration therapy or antibiotics may be required. A simple oral rehydration therapy (ORS) can be made by dissolving one teaspoon of salt, eight teaspoons of sugar and the juice of an orange into one litre of clean water.
Risk factors for enteritis necroticans include decreased trypsin activity, which prevent intestinal degradation of the toxin, and reduced intestinal motility, which increases likelihood of toxin accumulation. Vascular disease
Ischemic enteritis is uncommon compared to ischemic colitis due to the highly vascularised nature of the small intestine, allowing for sufficient blood flow in most situations. It develops due to circulatory shock of mesenteric vessels in the absence of major vessel occlusion, often associated with an underlying condition such as hypertension, arrhythmia or diabetes. Thus it has been considered to be associated with atherosclerosis. Surgical treatment is usually required due to the likelihood of stenosis or complete occlusion of the small intestine. Ischemic damage can range from mucosal infarction, which is limited only to the mucosa; mural infarction of the mucosa and underlying submucosa; to transmural infarction of the full thickness of the gastrointestinal wall. Mucosal and mural infarcts in and of themselves may not be fatal, however may progress further to a transmural infarct. This has the potential for perforation of the wall, leading to peritonitis. Radiation enteritis
Inflammation of the gastrointestinal tract is common after treatment with radiation therapy to the abdomen or pelvis. It is classified as early if it manifests within the first 3 months, and delayed if it manifests 3 months after treatment. Early radiation enteritis is caused by cell death of the crypt epithelium and subsequent mucosal inflammation, however usually subsides after the course of radiation therapy is completed.