What probiotic do you like the best?

[Astragal14]

Thank you too everyone for advice and suggestions! So waiting to hear back from the vet.
Question... one thing mentioned was fiber. If I'm reading correctly, a prebiotic has fiber, right? Maybe he'll benefit something like Fera prebiotic/prebiotic as someone here mentioned

Different prebiotics do different things. For diarrhea, you'll want a prebiotic fiber that increases bulk in order to firm up his diarrhea into normal poop. Psyllium is a popular option because it increases bulk by absorbing water (like the watery liquid in diarrhea). I'm not aware of any pre & probiotic combo products where the prebiotic is one that increases bulk (if anyone knows of one, let me know!), so you'll probably need a separate prebiotic and probiotic.

For probiotics, you'll want to pay attention to two things: total number of Colony Forming Units (CFU's) and the number of probiotic strains. More is better when you're dealing with diarrhea: you'll want anywhere from 10 billion, 15 billion, or more CFU's and about 10 or more probiotic strains (s.boulardii is unique because it seems to directly target diarrhea, but generally more strains = more diversity = better gut health). For reference, Forti Flora is so weak because it's a single strain with 100 million CFU's.