The aetiology is so far unknown, many theories exist. Oral cavity . Oral manifestations of Crohn s disease are not rare. Small aphthous ulcerations are the main finding. Oesophagus Oesophageal and gastic involvment in Crohn s disease is quite rare.
Genetic factors are of importance.
The common age at presentation of Crohn s disease is 15 to 35 years, but it can occur at any age. Duodenum Diarrhea, the main symptom of this disease, can be due to bacterial overgrowth in the small bowel, diminished water absorption in the large bowel, reduced absorption of bile acid in the distal small bowel or an elevated secretion of mucus in the distal large bowel and rectum. Steatorrhea can occur after large small bowel resection. Ileum About on third of all patients with Crohn s disease have only small bowel affection at the time of presentation. Ileum , a typical xray-finding.