Diagnosed fistula. Noticing dots of blood. Surgery? Treatment? What to do? Nitroglicerine ointment cure?

I got anal fistula diagnosed last friday.about 5 months a go i had abcess which bursted by itself.now i remember i had like attack of anal pain few years a go which put me to bed for a week but after was kind of fine.but still getting dots of blood on the toilet papier especially after heavy food or drinking alcohol.so i live with that condition for years now.at this stage doctor send me for mri scan and ultrasounds.and then he will decided what kind of surgery i do need.what are chances to treat that condition and what i have to do to help with it...is nitroglicerine ointment good cure too?