Autoimmune Crohn's disease – also known as regional<unk> , it can occur along any surface of the gastrointestinal tract. In 40% of cases, it is limited to the small intestine. Coeliac disease – caused by an autoimmune reaction to gluten by genetically predisposed individuals. Eosinophilic enteropathy – a condition where eosinophils build up in the gastrointestinal tract and blood vessels, leading to polyp formation, necrosis, inflammation and ulcers. It is most commonly seen in patients with a history of atopy, however is overall relatively uncommon. Infectious<unk>  In Germany, 90% of cases of infectious<unk>  are caused by four pathogens, Norovirus, Rotavirus, Campylobacter and Salmonella. Other common causes of infectious<unk>  include bacteria such as Shigella and E. coli, as well as viruses such as adenovirus, astrovirus and calicivirus. Other less common pathogens include Bacillus cereus, Clostridium perfringens, Clostridium difficile and Staphylococcus aureus. Campylobacter jejuni is one of the most common sources of infectious<unk> , and the most common bacterial pathogen found in 2 year old and smaller children with diarrhoea. It has been linked to consumption of contaminated water and food, most commonly poultry and milk. The disease tends to be less severe in developing countries, due to the constant exposure which people have with the antigen in the environment, leading to early development of antibodies. Rotavirus is responsible for infecting 140 million people and causing 1 million deaths each year, mostly in children younger than 5 years. This makes it the most common cause of severe childhood diarrhoea and diarrhea-related deaths in the world. It selectively targets mature enterocytes in the small intestine, causing malabsorption, as well as inducing secretion of water. It has also been observed to cause villus ischemia, and increase intestinal motility. The net result of these changes is induced diarrhoea.<unk>  necroticans is an often fatal illness, caused by β-toxin of Clostridium perfringens. This causes inflammation and segments of necrosis throughout the gastrointestinal tract. It is most common in developing countries, however has also been documented in post-World War II Germany. Risk factors for<unk>  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<unk>  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<unk>  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<unk>  is caused by cell death of the crypt epithelium and subsequent mucosal inflammation, however usually subsides after the course of radiation therapy is completed. Delayed radiation<unk>  is a chronic disease which has a complex pathogenesis involving changes in the majority of the intestinal wall.
Enteritis
Gastroenteritis
Colitis
Enterocolitis
Gastroenterocolitis
Stomatitis
Duodenitis
Lower gastrointestinal bleeding