On a completely totally anecdotal level I can relate to the varied length of time for poops.
My chameleon had several scary-long periods of no-poop. I don't remember exact time frames, but I think one was over a week. When it eventually came out though, everything looked good and healthy as far as I could tell... but I'm not above saying that I could have been doing something wrong with my husbandry that caused it.
I have a new baby now, and I've had him for about a week and a half. His poops are very small, but I've counted three so far that I could find in his cage.