After abdominal surgery the intestines are sometimes slow to re-start following surgical manipulation during the operation. I believe the medical name is "ileus". When I underwent colon surgery I was told that there were drugs that could be administered to nullify an intestinal ileus and you may wish to ask the surgeon about this.
regards
Morecambe
There is a procedure called a "pull through procedure" where a doctor removes the large intestines completely and connects the small intestines to the anus. This is done alot of times for people with really bad ulcerative colitis cases. I have no idea if this is an option for your girlfriend, but could be worth discussing and researching. From what I read, it greatly improves the life of those who have had it. Good luck, and keep us posted.