This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Entero enteric fistula is found in all except: March 2007 
Select and explain. 
A. Crohn's disease, B. Colo-rectal malignancy, C. Actinomycosis, D. Ulcerative colitis
D: Ulcerative colitis
Answer: D: Ulcerative colitis 
Explanation: Ans. D: Ulcerative colitis The principal causes of entero-enteric fistula in order of frequency are: Crohn's disease Diveicular disease Colo-rectal malignancy Radiation enteritis Tuberculosis Actinomycosis Complications of severe ulcerative colitis: Fulminating colitis Toxic dilatation (megacolon) Perforation Severe hemorrhage Cancer Extra-ailmentary manifestations-skin lesions, eye problems, liver disease, Sclerosing cholangitis is amongst the extraintestinal manifestation of ulcerative colitis.