Sometimes it retains it and then it gives much pain.

Sometimes it retains it and then it gives much pain. They say there is no way out except to have it operated upon. Formerly they called it a surplus intestine (of no use). But now, when medical science has advanced, they have succeeded in understanding the wisdom behind the construction of the human body by Omniscient Allah. They have now changed its name saying it is not correct to call it surplus intestine. It is not surplus, but is an important part of the intestine. What is it?