This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inflammatory bowel disease, Subject name: Surgery
Toxic megacolon is seen in: 
Select and explain. 
A. Carcinoma colon, B. Gastrocolic fistula, C. Ulcerative colitis, D. Amoebic colitis
C: Ulcerative colitis
Answer: C: Ulcerative colitis 
Explanation: Toxic Megacolon Toxic megacolon is a serious life-threatening condition that can occur in patients with ulcerative colitis, Crohn's colitis, and infectious colitides such as pseudomembranous colitis This decompensation results in a necrotic thin-walled bowel in which pneumatosis can often be seen radiographically Total abdominal colectomy with ileostomy and preservation of the rectum is treatment of choice for toxic megacolon. It serves the main purpose of removing the diseased colon and avoiding a difficult and morbid pelvic dissection.