I don't know about OTC meds, but I was told by my dr that diarrhea is a good thing in babies, as long as they are not getting severely dehydrated. It is happening to flush a virus out of a child's system, and while 2 days seems like a long time to be experiencing it, it's really not. Grace had vomiting and diarrhea for a week in total a couple months ago, and while it was an incredibly long week for everyone, she did not become dehydrated, and was able to shake it. We visited the drs every day in this time for constant check ups. So, I would not give those OTC, but honestly, you have to follow your own gut and the advice of your ped.
I would give no food, just water by mouth, and very small amounts at a time - a tsp every half hour will keep your baby properly hydrated without overloading their stomachs and making them vomit it back up. My ped told us nothing by mouth except water for 4 days, and then afterward the vomiting was under control, still no milk or milk products or anything heavy for another day after that, to help her stomach ease back into food, etc.
Like I said, follow your own instincts, and talk to your ped before trying any new med with AB. This is just my experience and my opinion!
HTH!
