Thrush is a yeast infection in your mouth. Its nothing dangerous but it can be painful. If the medication is the oral kind that I've used before you want to squirt it around so you get it all over the inside of his mouth.
Ty tomorrow that its painful explains so much. Hes been crabby and I bet thats why. Poor lil baby :(
My daughters had nystatin 3 times and it still wasn't gone so we decided to go the natural route with gentian violet, if it doesn't woot for you I would seek out that and do research, it stains but I was careful and I will probably only need to use it once more rather than 5 times a day for 3 weeks. Good luck:)