What happens when you hold your poop in a long time? do you get anus or rectal cancer?

You get bloated!: There is no evidence that "holding it in" causes any form of cancer. It can cause diverticulosis and hemorrhoidal symptoms! it is better to go when you have to go!

VoluntaryConstipatin: Waiting to go when you have to is probably not such a good idea.It can result in large volumes of stool in the rectal area which acts as a holding place for stool.The larger volumes must than be passed which can cause fissures, tears and because you have to strain more hemorrhoids.We know that chronic constipation is an issue with cancer ie people who eat diets high in fiber have a lower risk.