Please don't self diagnose and treat a RI. You may get lucky and relieve some symptoms but you have no idea the cause of the RI. F10 (various designations of the product are actually different things) is not an antibiotic fit for animal ingestion. I know that there are those videos of DIY RI cures but for the love of your snake, if you are going to keep it, find a decent exotic vet that can do a culture and find out exactly what the RI is and evaluate this snake for other complications.
The only way to properly treat this is with a vet's aid. Surrender this pet if you do not want to take the responsibility but for your sanity do not get another pet from that pet store.
Good luck and I hope you can get this under control.