Bearded Dragon BMs

Question
I have a 1.5 year old bearded dragon that hasn't had a bowel movement for a couple of weeks. I'm starting to think she may be impacted. She's not eating as much as she has. The substrate is ground walnut and seems to be fairly small grain.

How often do adult beardies have BMs? Do you think she is impacted?

Answer
Depending on what substrate she's on or what live prey she's eating, impaction can occur.  However, an 18 month old beardie is offically a full adult, and she may be starting the semi-hibernation called brumation that most beardies go through as winter approaches.  For a good description, read this:

http://www.biology.lsa.umich.edu/research/labs/ktosney/file/BDbrumate.html