As for Diverticulitis, my doctor just said that fiber is your friend and that if anything causes problems don't eat it again. He also said that some literature says some food products are problems and the next article says just the opposite.
The bottom line is that at out age an ounce of prevention is worth many pounds of cure. I wouldn't let anything medical bother me for a month.
FWIW, my colonoscopies(sp) have had few after effects other than a need to consume some syrup covered pancakes, along with anything else I can get into my mouth, in the first hour after I get home from the procedure.
No offense meant, but putting one off is not the best of ideas.
Here is a thread I started by asking if anybody had ever done one awake. The stories should make you want to reschedule pretty quickly...........
http://www.bikeforums.net/showthread.php?t=308313
There were over one hundred responses and over thirteen hundred views. The point is not that I have anything meaningful to say, but it is important to get this done.
Good luck.