Can a knife wound cause gastrointestinal fistula?

Yes: A knife wound to the abdomen is likely to cause a puncture to the intestines. When this happens the contents of the bowel can leak into the abdominal cavity. This requires immediate surgery to close the hole and wash out the contaminated abdomen. If there are many penetrating wounds or a delay in closure this can result in formation of a fistula-abnormal connection to the skin or other organ.

Knife wound: If the knife is long enough and the patient unfortunate enough to be on the receiving end of a piercing, then it is possible that the injury could result in fistulas with the gastrointestinal tract.