Background: Cytomegalovirus (CMV) colitis is commonly seen in patients who are immunodeficient or have inflammatory bowel disease. Among the gastrointestinal sites affected by CMV, the colon is the most frequently affected, though rectal involvement is relatively rare. Reactivated CMV proctitis primarily occurs in elderly patients with comorbidities and is quite uncommon in immunocompetent individuals. Patients with reactivated CMV typically present with symptoms such as diarrhea, hematochezia, or tenesmus. Case presentation: We report a case of a female patient with uncontrolled diabetes who presented to the clinic complaining of perianal pain. She had no history of diarrhea or rectal bleeding. Lower GI endoscopy reported a small, localized, approximately 0.5 cm swelling in the proximal anal canal in addition to sigmoid diverticulosis. The biopsy revealed a small ulcer at the anorectal junction caused by CMV and confirmed by immunohistochemistry. Unfortunately, the patient was lost to follow-up before antiviral therapy could be initiated. Conclusions: This case highlights an uncommon presentation of reactivated CMV proctitis in an older diabetic patient presenting solely with perianal pain. Clinicians should maintain a high index of suspicion for CMV infection in elderly patients with comorbidities, even when classical colitis symptoms are absent, to avoid delayed diagnosis and management.