It depends... If this is happening over a few weeks or months, it's probably nothing special. Just keep treating them, or see a doctor for in-office treatment, maybe with cautery or freezing. They'll eventually stop recurring. If it's happening over more than a few months, it might not be warts; although such late recurrence can happen, it is uncommon. See a doctor to confirm the diagnosis and for treatment.
How common is it for a case of genital warts once cleared to return years later? Does this show up in practice or studies often?
Pretty uncommon. Genital warts can reappear several years after an initial episode. There are no statistics, but it's clearly uncommon; I would guess it happens in under 1% (and certainly less than 10%) of people with genital warts. Some probably are new HPV infections, but of course that depends on risk of new exposure to and infected partner. It's an inconvenience, not a serious health risk. Good luck! Read more...