This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T., Subject name: Medicine
Toxic megacolon is most commonly associated with: 
Select and explain. 
A. Ulcerative colitis, B. Crohn's disease, C. Whipple's disease, D. Reiter's disease
A: Ulcerative colitis
Answer: A: Ulcerative colitis 
Explanation: Ans. A. Ulcerative colitisComplications of Ulcerative colitis:a. Massive hemorrhage.b. Toxic mega colon with perforation.c. Colonic epithelial dysplasia and carcinoma. The risk of neoplasia increased with duration and extend of the disease.