Lymphogranuloma Venereum (LGV) Proctocolitis Presenting As Small Bowel Obstruction in an HIV-Negative Man Who Has Sex With Men (MSM) on Pre-exposure Prophylaxis (PrEP): A Diagnostic Dilemma

Lymphogranuloma venereum (LGV) is an aggressive, sexually transmitted infection caused by specific serovars (L1-L3) of Chlamydia trachomatis. Historically considered endemic to tropical regions, LGV has re-emerged in developed nations in recent decades, predominantly affecting men who have sex with men (MSM). Its clinical spectrum is broad, ranging from asymptomatic infection to severe proctitis and proctocolitis, as well as systemic inflammatory manifestations. While buboes were once the hallmark presentation, proctitis syndrome has become the predominant clinical form in contemporary MSM populations, particularly among those engaging in anal receptive intercourse. The increasing use of pre-exposure prophylaxis (PrEP) and associated reduction in condom use have been implicated in facilitating LGV transmission in HIV-negative MSM, expanding the affected demographic beyond those living with HIV. Here, we report a case of a 31-year-old HIV-negative homosexual male patient on PrEP who presented with a two-week history of worsening abdominal pain, fever, nausea, tenesmus, and night sweats. Imaging revealed dilated fluid-filled loops of small bowel consistent with high-grade small bowel obstruction (SBO), prompting an exploratory laparotomy that was unrevealing. Postoperatively, the patient developed a muco-purulent rectal discharge, and further history revealed prior chlamydia infection and a sexual partner with inguinal lymphadenopathy. A rectal swab was positive for Chlamydia trachomatis by nucleic acid amplification test (NAAT), and LGV proctocolitis was diagnosed based on high clinical suspicion. Clinical, laboratory, and imaging features are presented in detail. The patient was started on a 21-day course of doxycycline, which led to marked clinical improvement, and his sexual partner was also treated. This case emphasizes the necessity of maintaining a high index of suspicion for LGV in MSM patients on PrEP who present with gastrointestinal symptoms mimicking SBO or inflammatory bowel disease, even in the absence of HIV infection. Prompt recognition and treatment are essential to prevent complications, including rectal strictures, bowel perforation, and unnecessary surgical interventions.