Just that really. If you are an adult without any illness or condition that could make a bowel movement troublesome, how long does it take you to have a poo??
I'd say it takes me 5 minutes at an absolute maximum but DH can take anywhere from 20 minutes to half an hour.
Usually he feels the need to go at the most inconvenient time for me, generally when I'm trying to finish cooking or plate up meals & then I have to contend with the feral toddler too.
AIBU to wonder why it takes him longer to have a poo than it takes me to commute to work??