Hi. My Hubby Has A Pimple Juzz Beside The Anal

Hi. My hubby has a pimple juzz beside the anal opening since 3months. Initially it used to bleed. But we consulted a gp n it was cured within a week. But now again dat single pimple is developing n its bleeding again. We r unable to get wat problm is this. Is this piles or fistula or some other thing?? Plzz help us. Thank u