Once in the morning, once in the evening, everyday. Once in a blue moon, there's an afternoon session.
As said earlier, I can't imagine eating and not pooping. If you drink and don't pee, you know something is wrong.
I remember having some morphine recently, then freaking out after finding out that lack of a bowel movement was a side effect. I was nervous for 2 whole days, eating extra, wasting time on the toilet seat, just waiting for anything to come out.
I was horrified til I saw that struggle turd on the 3rd day which might have been no bigger than 3 marbles glued together. It took like 20 minutes of straining instead of the usual 4, but what a glorious moment it waa to see that my body was working again.