We report the case of a 17-year-old male who was initially assessed for pain with defecation, bloody rectal discharge, and diarrhea, consistent with proctitis. Though proctitis is most commonly due to inflammatory bowel disease (IBD), infectious etiologies must also be considered, including sexually transmitted causes of infectious proctitis. In discussion of his sexual history, he identified as homosexual and acknowledged engaging in receptive anal intercourse. Rectal biopsies obtained via colonoscopy were culture-positive for herpes simplex virus (HSV), leading to a diagnosis of HSV proctitis and treatment with an appropriate antiviral medication. HSV proctitis is more common in individuals with high-risk sexual practices, including men who have sex with men. While this may be an uncommon diagnosis for pediatricians to make in practice, a high clinical index of suspicion for sexually transmitted infectious proctitis in those with risk factors must be maintained in order to facilitate appropriate testing, treatment, and counseling of affected individuals.