Occasional severe constipation is seen in ulcerative colitis patients with:

linical features of ulcerative colitis : The primary presenting symptom of ulcerative colitis is blood in the stools. Loose stools (or a decrease in stool consistency) for more than six weeks differentiates UC from most infectious diarrhoea. Extensive active UC 1. Chronic diarrhoea almost invariably associated with 2. Rectal bleeding, or at least visible blood in the stools. Such 3. Rectal urgency, tenesmus, 4. Passage of muco purulent exudates, 5. Nocturnal defecation 6. Crampy abdominal pain Proctitis alone : Usually present with rectal bleeding, urgency, tenesmus,and occasionally severe constipation. Simple fistulae may occasionally occur in UC, recurrent or complex perianal fistulae should always raise the suspicion of Crohn's colitis. Ref: Journal of Crohn's and Colitis (2012) 6, 965-990.