Mycoplasma Genitalium, or “Mgen,” is a type of bacteria commonly found in the urinary or genital tract. It usually won’t cause any problems, but if overgrowth occurs, you may experience abnormal genital discharge, burning with urination, and rectal pain and discharge. Untreated Mgen can result in pelvic inflammatory disease (PID) in patients assigned female at birth which can cause fertility complications in the future.