<prompt> Entero enteric fistula is found in all except: March 2007Crohns diseaseColo-rectal malignancyActinomycosisUlcerative colitis  <response>: Ans. D: Ulcerative colitis The principal causes of entero-enteric fistula in order of frequency are: Crohns 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. 