Hemorrhoids are anorectal disorders characterized by venous dilation and mucosal inflammation. Recent genomic analyses identify nitric oxide synthase-3 (NOS3) as a key risk gene; sapropterin—an FDA-approved 6-R-tetrahydrobiopterin analog for phenylketonuria—is predicted to down-regulate this pathway. Objective: To evaluate the anti-inflammatory effect of sapropterin on NOS3, cyclo-oxygenas…