<prompt> Apple core appearance on barium enema is seen in?Carcinoma ColonTB caecumCrohns diseaseUlcerative colitis  <response>: Ans. a Carcinoma ColonRef: Bailey 26th ed. 170 On double contrast barium enema of the rectum and distal sigmoid colon demonstrates a typical annular constricting carcinoma of the colon with overhanging edges on both the proximal and distal margins forming a so called apple-core lesion. 