OBJECTIVES: The aim of study was to compare the accuracy between rectal water 
contrast transvaginal ultrasound (RWC-TVS) and double-contrast barium enema 
(DCBE) in evaluating the bowel endometriosis presence as well as its extent.
DESIGN AND SETTING: 198 patients at reproductive age with suspicious bowel 
endometriosis were included. Physicians in two groups specialised at 
endometriosis performed RWC-TVS as well as DCBE before laparoscopy and both 
groups were blinded to other groups' results. Findings from RWC-TVS or DCBE were 
compared with histological results. The severity of experienced pain severity 
through RWC-TVS or DCBE was assessed by an analogue scale of 10 cm.
RESULTS: In total, 110 in 198 women were confirmed to have endometriosis nodules 
in the bowel by laparoscopy as well as histopathology. For bowel endometriosis 
diagnosis, DCBE and RWC-TVS demonstrated sensitivities of 96.4% and 88.2%, 
specificities of 100% and 97.3%, positive prediction values of 100% and 98.0%, 
negative prediction values of 98.0% and 88.0%, accuracies of 98.0% and 
92.4%, respectively. DCBE was related to more tolerance than RWC-TVS.
CONCLUSIONS: RWC-TVS and DCBE demonstrated similar accuracies in the bowel 
endometriosis diagnosis; however, patients showed more tolerance for RWC-TVS 
than those with DCBE.