Radiological diagnosis of enterocoele is possible using evacuation proctography, but the standard technique must be modified to reveal the small bowel. Since prolapsed bowel is interposed between the vagina and rectum, diagnosis may be possible using vaginal endosonography. We describe a simple ultrasound technique to diagnose enterocoele, which has been validated by comparison with proctography. 17 women were examined with vaginal endosonography, and a diagnosis of enterocoele made if bowel was visualized in the rectovaginal space when bearing down. The findings were compared with subsequent proctography. In eight cases (47%) bowel prolapsed into the rectogenital space during straining, obscuring the rectum, while this did not occur in the remaining nine subjects (53%). Proctography confirmed an enterocoele in six of the eight cases in whom it had been diagnosed on endosonography, and confirmed the absence of enterocoele in all of the nine cases negative on endosonography. These values gave vaginal endosonography a sensitivity of 100% and specificity of 82%, with a positive predictive value of 75%, and negative predictive value of 100% for a prevalence of abnormality of 0.35. Vaginal endosonography is a quick, easy and convenient alternative to evacuation proctography for the radiological diagnosis of enterocoele.