I don't think the question is "Does it work" because it is a fiber supplement and fiber does "work" and it even does all the things it claims because ... fiber does those things!
The better question is ... do you need extra fiber in your diet, is this the best way to get the extra fiber, and is the price reasonable.
In my opinion - you're better off eating more veggies but if you want to supplment with fiber there are many less expensive ways to accomplish the same thing.
"Getting solid information is easier than ever. Getting misinformation is even easier." - Kaplods
Maintaining for two years and I eat whatever I want - just not however much I want. Details here.