He could be impacted. First try some warm water baths, 75-80 degrees. There's a frog first aide article on the left that says something about salt and buldging butt, but.. That had to do with infection in intestines. Could be a few things, but I would try the bath first. I also added honey, 1drop per ounce. Figuring that sugar helps bowels move, and helps with energy levels.