Inflammation can cause effusion, most commonly due to inflammation that increases pelvic tissue exudation, so that an ultrasound examination will reveal effusion in the rectal fossa of the uterus, which is often >2 cm and can cause recurrent lower abdominal pain, especially during menstruation, which is often aggravated during sexual intercourse after exertion. In addition, if there is local inflammation in the fallopian tubes that leads to obstruction, then there is no way to drain the ooze from the tubes, so it will lead to effusion. Ultrasound examination will reveal local thickening of the fallopian tubes with fluid. It is recommended that anti-inflammatory treatment be actively given, either with antibiotics or surgery.