Another thing to consider is Dioralyte - all Pharmacies sell this over the counter in sachets if your piggy has runny poops. Mix a small amount with water and give to him, helps replace lost electrolytes and helps to ward off dehydration.
It all sounds very much 'overload' and worrying but I used this when Harley refused all food/fluids when he was on Baytril, had awful diarrhoea and was extremely poorly 8...if your boy is taking fluids himself or via a syringe, he should remain hydrated. A good thing to do is pinch the fleshy area between his shoulders gently, if the skins easily falls back into place, he's hydrated but if it takes a few seconds, could need more fluids.
Diarrhoea can be a side effect of Baytril and worth contacting your vet to update - they may change it to Septrin (much kinder for their tums and in taste as well)
You can pm me if you wish for any concerns you have, will be on here most of the day between piggy bed washing rolleyes - know how hard it is to see your babies poorly :...