I wonder if maybe a health food store could suggest a product or supplement? I just don't know. Diet pills in any form scare me - there have been just too many times the FDA comes back and says "Opps, we made a mistake and this product causes harm".
I used to have IBS also (a serious problem), but I was able to correct everything through diet. Adding more grains and veggies, cutting back on meat, seafood, dairy, drinking more water, less tea/coffee, etc.
Trust me I know it is tough not to have insurance, I'm in the same boat.
Hopefully someone else will answer your post with a good recommendation.