Lol, had the same discussion a couple days ago with my friends, some of them crap like 20 minutes after every meal, i have one who craps about 4 times a day and is in and out in 2 minutes. Then theres me, I take a crap every day or every other day or so and am in there for 20 minutes a time usually, most ever was 50ish and i was sick.
Longest I've ever gone without shitting was 5 days. On vacation and our toilet in the hotel was gross and small, so i decided to see how long i could last, made it to the day before we left to go home and couldn't hold it in. Some of the side effects of not shitting included dizziness, nausea, faintness, and limited appetite... it was a terrible idea