My father (81) suffered a perforated bowel after a colonoscopy.  The colonoscopy was performed because he reported changed bowel habits.  He underwent emergency surgery where they removed a section of the colon.  Then a couple of weeks later he had to have surgery again because of adhesions and they removed more of the bowel.  Between the two operations he suffered a urinary track infection and had also been nauseated either because of the infection or the adhesions (I am not sure).  He lost a significant amount of weight over the six week stay in hospital but since going home has put on about six kg (in a period of about seven weeks).  He continues however to vomit at first every ten days or so but in the last week, has been sick three times.  This concerns him of course.  The doctor has done blood tests and a CT scan but says nothing untoward is obvious.  Any ideas?  Would it only be diet even though he is careful about what he is eating and there appears to be no pattern involved as far as food, days between vomiting, other than he vomits in the mornings.  Your help would be greatly appreciated.