Trichomoniasis (referred to as trich) is caused by a protozoan, Trichomonas Vaginalis, a parasite that can infect both the vagina and the urinary tract. In men, the infection will only ever occur in the urethra (the tube that carries urine to the penis).
In men, trich tends to show no symptoms whatsoever. But, if symptoms do show up, a man will typically experience discomfort in the urethra or an inflamed and sore glans (head of penis). For women it is usually a far more uncomfortable infection. The protozoan can live for years in the vagina and the woman may experience no ill effects. However, when it does start developing symptoms they are usually quite noticeable. A woman's genitals may become painfully inflamed or itchy. As well, a yellow, frothy discharge from the vagina could occur. Sexual intercourse may be painful and some women even experience lower abdominal pain.
Trich infections can be contracted through sexual intercourse, the use of infected washcloths or towels, and by a pregnant mother to her offspring. It is very important to clean all towels, washcloths, hands... anything that has come into contact with the infected area, immediately. Children can be infected by trichomoniasis too, and this is why cleanliness is such an important issue.
The doctor will prescribe a medication called metronidazole that can clear up the infection. The doctor may also treat the partner because he/she may have the infection also. By doing so, it will lessen the chance of the infection recurring.