A lice-killing lotion containing 1% permethrin or a mousse containing pyrethrins and piperonyl butoxide can be used to treat pubic (crab) lice. These products are available over-the-counter without a prescription at a local drug store or pharmacy. These medications are safe and effective when used exactly according to the instructions in the package or on the label. Lindane shampoo is a prescription medication that can kill lice and lice eggs.
Trichomoniasis is another type of vaginal infection. It is caused by a single-celled parasite that is usually spread through sex. In addition to causing bleeding after sex, it can also cause vaginal discharge and itching.
One of the most common reasons women experience abdominal pain after sex is that they have a urinary tract infection and did not realize it. See a doctor! This does not apply to long term issues with this pain (i.e. if you have this pain every time after sex for years).