Hi Stankalot, the prescription probiotics go by the name of Biofermin here in Japan (I don't know if you can get the exact same brand elsewhere). It's bifidobacterium made through a yeast process (it's a beneficial yeast, unlike a lot of other yeasts).
I'm also going to look into Lactibacillus prescription. That probiotic creates a higher acidity level in the gut, making harmful bacterial growth more difficult.