Your poop is acidic when the pouch is new. Slowly it returns to normal pH . What I've seen is that mine is particularly acidic or runny at night 2 hours or so before bed. So I finish up my last meal before 8.30 and hit the bed at 12. Also a thick output doesnt seem to bother me much. I'll say try avoiding anything fried or dairy when you feel its too acidic. I personally go for a high protein and fat diet like red meat, fish, chicken. They are slow digesting so help me with controlling the number of times I have to go.