Trichomoniasis, also known as trich (say "trick"), is an infection caused by a parasite. It spreads through sexual contact (sexually transmitted infection).
Most people don't have any symptoms of trich. But it may cause symptoms such as an abnormal discharge from the vagina or penis and pain during urination or sex.
The infection is treated with antibiotics. If you're infected, it's important for your sex partner to take medicine too.