Why is the anus so much smaller than the rectum? /u/LateBoysenberry6579 No such thing as stupid questions

Off the back of a toe curling bowel movement it got me wondering why does our bodies amalgamate such monstrous stool movements to pass through a relatively small (not for everyone I guess) anus hole. Excruciating.

Thank you for your answers.

Off the back of a toe curling bowel movement it got me wondering why does our bodies amalgamate such monstrous stool movements to pass through a relatively small (not for everyone I guess) anus hole. Excruciating.

Thank you for your answers.