I'm scheduled for my subtotal colectomy Aug. 3. When I went for my second oppinion, the doctor was surprised that my surgeon had tested my small intestine. He said it wasn't necessary unless I had a history of vomiting, which I don't. So, if your constipation leads to vomiting, then as far as I understand, you'll need to have the small intestine checked out. The procedure isn't bad at all: you drink some vanilla barium stuff, walk around the office for 1 to 3 hours, while they take x-rays every 15 minutes or so.