Probiotics are great, but if the wrong kind are taken or too much, they can cause sever gas which can also smell pretty bad. I find that if I place the end of the long catheter in the water when I let out gas, the water absorbs the smell. There is also a great product on the market, Poop Pourri and it works real well. I take anti-gas pills and they help a lot more than the probiotics did for basic discomfort.