Baby poo

So my 9 month old had a mild stomach bug, it's been about 12 days now since he first started with very watery diarrhea. He's been having a hard time recovering, he has a little but if diarrhea still but it has been getting thicker the last 2 days.

Here's where I'm concerned, when he poops it's like cottage cheese, his poop has always had a little bit of that curdy stuff in it but lately it's been very thick with the curds. He is formula fed and eats some real food. Any insight is welcome :)