Gonorrhoea is an STD which is both treatable and preventable. Infection from anal sex may cause an inflammation of the anus. Untreated gonorrhoea can cause sterility, arthritis, heart problems and central nervous system problems in both men and women. It can also lead to major mental health disorders if not treated. In men it can affect the testicles.
Treatment involves a course of antibiotics which can cure the disease.
Even if there are no symptoms, or if the symptoms clear up, the disease is quite likely to still be there. If you have had unprotected sex you should have a test for STD's. Condoms are the best way of reducing the risk of catching gonorrhoea. Finally, gonorrhoea may cause infections of the mouth and anus. An oral infection normally produces no symptoms.