Lymphogranuloma venereum (LGV) is an uncommon sexually transmitted disease caused by certain serotypes of Chlamydia trachomatis. It occurs in three stages - primary genital lesion, painful inguinal lymphadenopathy, and potentially years later, proctocolitis. Diagnosis is based on clinical findings and tests for C. trachomatis. Treatment involves doxycycline or erythromycin for 21 days along with drainage of infected lymph nodes.