Snake's body seemed to swell with fluid before pooping

About two weeks ago, I noticed that my BP's body seemed to be puffy, almost as though he was filled up with fluid. After a couple of days, he pooped and the swelling/puffiness went right away. Well, a couple of days ago I noticed that the swelling is back. I'm currently treating him for RI (have been treating him for 2 weeks). I'm just trying to figure out if the swelling/puffiness is associated with bowel movements, or if it could possibly be associated with the RI.

This is my first BP and I just got him April 24. I was told that he was 4.5-5 months old.
http://s1156.photobucket.com/user/Gi...c9cc2.jpg.html

http://s1156.photobucket.com/user/Gi...8d95d.jpg.html

I believe it is associated with the antibiotics. I just went through this with a RI on a similar age Ball. I believe it is the antibiotics that "back them up". Vet says: soak your snake in luke warm water (more on the warm side) everyday, this will also help with the RI. Also you can gently massage her body as she crawls around on you to get things moving down there. My vet seemed not concerned at all about this, but as long as I was there she gave the snake a quick enema with a very small catheter and a water/lubricant mixture. Everything your describing and the pictures were exactly what I had. If you want to discuss it I can PM you my number to call. The antibiotic didn't end up working in my case so I ended up using an over the counter product called Tylan 200 and it wiped it out right away.