Boyfriend is prone to thrush

A little bit of a background story, I’ve been with my boyfriend now for a very long time. He first got thrush when I was on antibiotics and we had sex. We realised antibiotics give him thrush ( he’s been on them a few times and so have I) so we decided not to have sex during this time. He’s a very clean guy showers every day but now seems to be prone to it.

Has anyone got any advice we’re TTC and it just keeps getting in the way he’s been to the doctors but they don’t do nothing.