But this symbol of procreative energy and male power also contains evidence of a medical condition that can curb fertility and hinder sexual relations, medical doctor Francesco Maria Galassi said. "The disproportionate virile member is distinctively characterized by a patent phimosis, more specifically a shut phimosis," he says.
In other words, Priapus' weenie seems to have a foreskin that couldn't fully retract: "It is a condition that causes pain, infection, and problems during sexual intercourse," Galassi adds.
So why would such a condition be shown in a fertility god? Galassi, who describes his theory in Urology, says the first-century painter may have wanted to report "a high prevalence of that anatomic defect in Pompeii." That could also explain why so many anatomical votive artifacts (showing a penis with closed foreskin at the top) were used in Pompeii between the second and fourth centuries BC to seek removal of that very condition.