On colonoscopy, the mucosa of the colon typically looks normal, but biopsies of affected tissue usually show deposition of collagen in the lamina propria, which is the area of connective tissue between colonic glands. Radiological tests, such as a barium enema are also typically normal.
Collagenous colitis
Microscopic colitis
Diversion colitis
Chemical colitis
Lymphocytic colitis
Cytomegalovirus colitis
Ulcerative colitis
Ischemic colitis