Samantha,
No, you're not doing something wrong.....some beardies simply go in their bathwater because they don't want the mess in their tank, so they hold it until you give them a
bath. And believe it or not, the males are more likely to hold it until bathtime than the females are. At least that's the case with my three.
Charlie NEVER has a bowel movement unless he's in his
bath, and Ming will also go while in the water, more often than not. However, Eden, my only female, will go any old place she pleases, and then walk through it and smear it over her tank, and couldn't care less, unless I don't clean it up right away......then I get the beardie "death glare" and the
black beard! LOL Cheeky little thing has her "beardie slave" trained right
Seriously though, some beardies prefer to go in their
bath, and some don't...it all depends on the beardie.
If you WANT him to go in his bathwater, then one way to get him to do that, is to make the bathwater very, very warm (but not hot) and
bath him in a deeper container, making the water deep enough so that he can't just stand on the bottom, but has to swim, Generally the combination of very warm water and exercise will produce a bowel movement very quickly, unless they're constipated, and even if they are constipated, they should still go, although it may take a bit longer.
However, if you make his bathwater deep enough so that he has to swim, and he has nothing to hang on to, and no way to get out of the water, then don't leave him unatteded in his
bath for more than a minute or two, not only because he may get tired and could drown, but also because if he does produce a bowel movement for you, you don't want him
drinking the bathwater once he's gone in it, or it could make him sick.
Hope these suggestions help!