Dolly Parton is no stoner -- at least, not anymore ... 'cause the country legend says she underwent surgery to have some pesky kidney stones removed last month.
Parton issued a medical update in the wake of rumors that she was suffering from stomach cancer -- rumors that Dolly insists are complete hogwash.
But the kidney stones were real -- so the 69-year-old went under the knife 3 weeks ago to clean house.
"I am doing just fine," Dolly says ... "I am back to work and last week I was at Dollywood filming parts for my new movie 'Coat of Many Colors.'"
So in conclusion -- stones are gone, boulders remain intact.