Differential diagnosis

The differential diagnosis is influenced by the presentation, a principal factor being the age.

• Crohn's disease
• infective colitis is often a cause of one episode of colitis which is mislabelled as ulcerative colitis e.g. salmonellosis, shigellosis, Campylobacter, amoebiasis. In the immunosuppressed patient then one must consider opportunistic infections e.g. cytomegalovirus, herpes virus, Cryptosporidium, Mycobacterium avium intracellulare.
• colonic carcinoma, adenoma - diagnosed on endoscopy, particularly important in the elderly
• diverticulitis - not in childhood
• irritable bowel disease, which would tend to occur in the young, and has early morning explosiveness, not tending to be bothered at night.
• ischaemic colitis - these patients may have a history of vascular disease with sudden onset of pain, and thumb printing on plain abdominal radiography or barium enema. It does not occur in childhood.
• post-radiation colitis, the diagnosis of which is based on the history