There is considerable overlap between these 3 groups. Unique type of T cell lymphoma associated with coeliac disease. Tropical Sprue unknown aetiology, responds to broad spectrum antibiotics. Second small peak in elderly. Malignancy increased incidence of small bowel, gastric and colonic adenocarcinoma in patients with Crohn's disease.
Inflammation spreads through the wall which has the consistency of wet blotting paper.
Perforation is common. Usually in caecum and right colon - may bleed massively. Diverticular Disease saccular outpouchings of intestinal wall. These diverticula bulge out at sites where vessels enter colon wall, i.e. between mesenteric and antimesenteric taeniae. Associated contractile changes in circular muscle.