A 25 year old male presents with a history of chronic diarrhea. Pathological examination reveals cryptitis and crypt abscesses. The likely diagnosis is:

Though chronic diarrhea may be found in both ulcerative colitis and crohn's disease, cryptitis and crypt abscesses are characteristic findings of ulcerative colitis. So ulcerative colitis is the single best answer of choice. Ref: Harrison's Principles of Internal Medicine, 16th Edition, Pages 1176-84; Davidson's Principles and Practice of Medicine, 19th Edition, Pages 808-817