I need to have sigmoid resection due to stricture from diverticulitis, I would like to know the chances of stricture coming back after operation?

If the stricture- -is not from a prior surgery, it should not come back. Also an interesting fact about diverticulitis is that the whole area that has diverticulosis does not have 2 B excised, & the problem goes away.
Probably very. low unless you have repeated attacks of diverticulitis again. Or some other cause for narrowing.