It's been less than a week, right? That's about when my colon would shut down. I had a horrible time of it, laxitives and stool softeners, I spent most of the time on chemo trying a balancing act between addressing the worst block up I've ever had and when my system said, "ok, too many laxatives, now I'm gonna make you pay!" I would call your doc and let him have it all, it may make you feel better, hearing "that'll happen" from the doc.
"Our greatest glory is not in never falling, but in rising every time we fall." -Confucius