Gonorrhea is caused by the bacterium Neisseria gonorrhea. The bacterium can enter the body and cause gonorrhea infection when the mucous membrane (soft skin covering all the openings of the body) comes into contact with the mucous membrane secretions, semen, or vaginal fluid of an infected person during vaginal, oral, or anal sex.
Gonorrhea can affect the urethra (the tubes that carry urine out of the body), lining of the eyes, the throat, the anus and rectum, as well as the fallopian tubes, uterus, and cervix in women, because the bacterium Neisseria gonorrhea enters and grows in warm, moist areas of the body.
Any time infected secretions or fluids come into contact with a mucous membrane of the body, transmission is possible, even if the penis or tongue does not fully penetrate the vagina or anus. For this reason, women who have never had anal sex can still get gonorrhea in the anus or rectum, because the bacteria can be transmitted when wiping secretions with toilet paper. Also, gonorrhea in the eye is possible when discharge carries the disease into the eye during sex or hand-to-eye contact with semen or vaginal fluid.
Vaginal delivery of a newborn by an infected mother may also cause gonorrhea to occur.