56 year old man with longstanding history of bowel problems since he was 20 years old. He has episodes of diarrhoea with blood-stained stools, sometime with mucous. There is no constipation.
The colon distal to the caecum shows diffuse mucosal ulceration with pseudopolyp formation. These appear as irregular raised mucosal tags. The ascending colon shows some more nodular areas. The caecum and terminal ileum are spared.