I soaked the sulcata tortoise today in warm tepid water that was as high as his chin. He seemed to extend his arms straight forward, and his legs out at an angle. It would then start periodically blowing bubbles from underwater, ffffttt, like a farting sound. That is, from his mouth or nose, NOT his butt.
Like a child playing in a swimming pool. He went ftttt every few seconds repeatedly.

I wasn't sure if it was straining to poop or what so I picked it up and turned it over and it promptly sprayed white pee all over my shirt, but no brown stuff.

It had eaten less recently. It has peed and pooped still but I suspect it has pooped less than usual.