Probiotics in general are supposed to replenish the good bacteria in your digestive system. These bacteria help in breaking down food for digestion. I'm hoping it will help me digest fats and IF better. Some say that people who are lactose intolerant and who take probiotics can actually start to be able to digest lactose again. If you are getting gas and bloating, it could be from having a hard time digesting, and the friendly bacteria could help with that.
Probiotics are promoted more for problems with diarrhea but can be helpful for constipation too. I would try a different type of probiotic than the one you are on now, and if you still don't see results then I would think they won't be helpful to you.