Our cat had horrible diarrhea and powerful stinky farts too, all because I gave him Whiskas Temptations cat treats for only one week and the diarrhea lasted for 5 MONTHS even though I had thrown out the treats right away. I tried many different natural remedies first and nothing was a permanent solution. Finally took him to a vet who prescribed Flagyl and Albon (liquid form), which we had to force feed into his mouth and the trauma made his diarrhea far worse -- he ended up pooping diarrhea on our bed, on the sofa, on top of the air conditioner, and in every room of our place! The medication did nothing!
I urge you to read this website immediately: catinfo.org. It's LOADED with valuable information, including about IBD (Inflammatory bowel disease). Dr. Lisa Pierson wrote this website and has helped our cat tremendously!!!
Dr. Pierson's advise and information solved the problem with just giving the right food that nature intended for cats -- we all should know that cats are carnivores. The ideal food she recommends is raw food you make yourself, her recipe is on her website. But I opted for her plan B, which is commercially prepared frozen raw food (Nature's Variety brand), but our cat didn't like it at all, even though I tried mixing it with things he does like. So I had to go for her plan C, which is canned food. First I tried a brand she recommended, Nature's Variety canned chicken, and he DID have solid poop finally! But he ate less and less of it, so I panicked and bought a canned brand which was NOT on her recommended list, Pet Promise canned chicken (only because I happened to have it) -- it had no hormones or by-products, but it did have rice, and my cat pooped diarrhea on our white comforter a second time! You will see in Dr. Pierson's website that she doesn't recommend giving cats any grains because they're carnivores. Then I tried Wellness grain-free canned chicken, which is one of the brands she recommends on her website -- he likes it and has been having solid poops ever since!!!!!!
Just so you know, before we were referred to Dr. Pierson and her website, we were giving him Innova Evo dry food. The weird thing is that he didn't have problems before I gave him the cat treats, but the treats had corn in it which may have been the culprit as I've heard corn can cause problems for cats.
We're so happy and relieved that our cat's chronic diarrhea problem had a solution AND it turned out to be such a simple, healthy and inexpensive solution after all!!! All that horrible stress is over for us and our cat! PLEASE read her website!