If your husband's cancer is too low, ie, in the rectum, then the whole rectum will come out. Such was the case for me. I have a permanent colostomy, my rectum, anus and some butt muscle was removed and, (no way to say it clinically) my butt sewn together. My cancer was very low and even if they had been able to save the anus I would likely not have had any control of it since they were cutting so close that the nerves would have suffered. My wife says that one would have to look close to see that there is no "crack" and I have gotten used to the c'stomy. It is a learning curve thing. I had a few accidents, they are disturbing and disgusting but the way I see it, it took me several years to learn how to go potty the first go 'round so it stands to reason that learning a new way to do it also will take time.
As for the 'roids, after the surgery they will no longer be any problem since even if they remain there will be no daily irritation of feces moving over them or straining of nearby muscles. It can be though of as one advantage of a c'stomy.