I've been taking bentyl now for about 3-4 weeks. So far, I think it's wonderful. It helps not with just abdominal cramping, but also bladder cramping, and stomach cramping (all of which I have). It's almost like a muscle relaxer or the equivalent. The only thing I would recommend is to take it at night at first to see how it makes you feel. It doesn't cause me any side effects at all, so I can take it any time of the day. If you don't like the way it makes you feel, you have complete control over whether to take it again.
Best of luck to you!