Three-dimensional (3D) rendering may be employed during transvaginal rectal water-contrast transvaginal ultrasonography (RWC-TVS) for detecting the presence and describe the characteristics of rectosigmoid endometriosis. This study aims to evaluate the impact of bowel preparation on the diagnostic parameters of 3D-RWC-TVS in women with suspicion of rectosigmoid endometriosis.

An accurate diagnosis of the presence, location and extent of the rectosigmoid endometriosis is of paramount importance for the clinicians in order to inform the patients on the potential surgical or medical treatments. It is well established that transvaginal ultrasonography is the first-line investigation in patients with suspicion of deep infiltrating endometriosis. An improvement in the performance of transvaginal ultrasonography in diagnosing rectosigmoid endometriosis may be obtained by using rectal water contrast during transvaginal ultrasonographic scan. In the last years, three-dimensional (3D) rendering has been employed during transvaginal ultrasound for benign gynecological diseases.

Inclusion Criteria:

- pain and intestinal symptoms suggestive of rectosigmoid endometriosis

Exclusion Criteria:

• previous surgical diagnosis of intestinal endometriosis
• previous radiological diagnosis of intestinal endometriosis (based on Magnetic Resonance or double-contrast barium enema
• history of colorectal surgery (except appendectomy)
• contraindications to bowel preparation or computed colonography (such as non-- compliant patients and rectal malformations)
• previous bilateral ovariectomy
• psychiatric disorders

Patients with suspicion of rectosigmoid endometriosis