I have heard that incontinence is a high risk with this surgery.

Have they explained just what the problem IS?

With my Tasha, she is very "well developed" and her stools tend to be too small to press the glands and clear them naturally. My vet told me to bulk up her stools, using canned pumpkin. (NOT canned pumpkin pie filling, that includes spices and other things). I give her 2 tablespoon twice a week with her meals and this has worked for 2 years now with no needed manual expression.