<prompt> A middle aged male, who is a diagnosed case of chronic ulcerative colitis, presents to emergency with fever and diarrhea for 1 week and acute onset pain abdomen for 6 hours. An erect abdominal X-ray was taken as shown. What is the likely diagnosis?Pseudomembranous colitisAdenocarcinoma colonPneumatosis intestinalisToxic megacolon  <response>: X-rayshows massively distended transverse colon,ahaustral left colon -History of fever diarrhea Toxic megacolon: - Life threatening - Occurs in patients of UC and CD . - Diameter 6 cm - Medical management- Stabilization Fluids IV anti-biotics - TOC - TAC with Ileostomy PMC - No colonic distension, fever diarrhea Adenocarcinoma colon - No massive distention, fever diarrhea Pneumatosis intestinalis - Collection of air in the wall of intestine. 