Peggy, I wonder (again) if he has a food allergy/sensitivity?
Jeddie had really foul smelling poops, often soft and "sticky. I HAD to scoop them as soon as he deposited them - even waking me up from the smell. As an aside, Beau had really smelly poops when he was eating dry food. Somewhat suddenly last September, Jeddie started having runny diarrhea. It really stank! And it made him agitated. He started peeing outside the box again.
I spoke to the vet and she said it sounded like IBD or a food issue. I mentioned that he ate fresh catnip and she said that can cause vomiting or diarrhea in some cats. I had my suspicions about one food brand because I had added a new flavor of it right before the diarrhea started, so I stopped it and the catnip and things slowly cleared up. I reintroduced catnip and had no problems. His stools are well formed and way less stinky. Sometimes, I don't even noticed he has pooped until it is LB scooping time.
I looked at the ingredients in the food I was feeding and it seemed like the only thing it had that the other foods didn't was dried egg product. Then I noticed that one of the Innova foods I was feeding had that in it so I have stopped feeding that as well.
Jeddie acts so much happier now. Incidentally, Beau has gotten more playful again since I eliminated that one food ingredient and I didn't even think he had any "digestive" issues.
Currently, I mix 1:1:.75 - Wellness, Sophisticat (lg cans ea) and water (for about 33 ozs total), plus I add a packet of FortiFlora and an 1/8 tsp taurine. that makes up enough food for all four cats for one day or a little longer. It was one day when I had five.
Look at the ingredients in the foods you feed and see if anything "jumps out" at you. I would not have thought that egg could bother them, but apparently it did. I also avoid grains, particularly wheat and corn, and soy as much as possible.