Good luck with your small bowel test. When I had mine (before my TC) my doctor said because of my constipation, they wouldn't give me barium to swallow because it's so hard to get out, but instead gave me something else to drink. It was horrible, tasted like stale cough syrup and as soon as the test was over, I threw it up....but I didn't have that barium stuck in me for days and days. Just something to mention maybe.
Let us know how it goes. I hope things turn out ok. If your small bowel is working, then why are you still constipated? Do the doctors have any idea??