UT tended to cause it for me when I over did it. It's not recommended to take large amounts of urine for over 2-4 weeks. When symptoms are relieved, it's best to taper off to a maintenance dose. Many people say "drink drink drink" to no limit but I personanlly don't agree with this recommendation because it didn't work out this way for me.
If anyone gets diarrhea they'd be wise to put a stop to it any way they can, IMHO.