Kitten Question

We rescued a feral kitten a couple months ago that was out back from our house. It looked like maybe something happened to mom, or the got separated because a huge thunderstorm rolled through that day. The kitten ended up having a pretty bad case of Giardia and worms. He’s all good now after treatment but his gut never seems to have balanced out. Even having tried a special diet of digestive care food the vet suggested, he still has pretty loose stools. Otherwise, his energy and health seems great. Any searches I do online makes it sound like loose stools is an emergency situation, but he seems absolutely fine. Has anyone else experienced this?

Edit: We have been giving him the daily probiotics since shortly after we found him. One packet a day, divided up with half in the morning and half in the evening. Morning and evening meal is Iams wet kitten food, and he snacks on Iams dry throughout the day.