As of 2015, vaginal sonograms are frequently able to accurately display fluid present in the endometrial cavity, according to the Journal of Ultrasound in Medicine. The presence of this fluid is a risk factor for developing a disease, as can be a symptom of an existing one.
The endometrium is the inner lining of the uterus, states WebMD. Ordinarily, the lining thickens and thins according to hormonal fluctuations, and does not contain any fluid. Signs of fluid inside the endometrial cavity can cause pain and digestive difficulties, states the NLDA website. However, to be certain that endometrial fluid is the cause of such problems, it is necessary to have the area imaged using a sonogram. A transvaginal ultrasound, also known as a vaginal sonogram, can provide accurate images of the inside of the uterus, according to MedlinePlus.