Computed tomographic colonography vs rectal water‐ contrast transvaginal sonography in diagnosis of rectosigmoid endometriosis: a pilot study

OBJECTIVES: To compare the performance of computed tomographic colonography (CTC) and rectal water-contrast transvaginal sonography (RWC-TVS) in the diagnosis of rectosigmoid endometriosis, and compare precision in estimating the length of the rectosigmoid nodules and the distance between the nodules and the anal verge. METHODS: This prospective study included 70 patients of reproductive age with clinical suspicion of rectosigmoid endometriosis. Patients underwent RWC-TVS and CTC before laparoscopic excision of endometriotic nodules. The findings of RWC-TVS and CTC were compared with surgical and histological results. RESULTS: Of the 70 patients included in the study, 40 (57.1%) had rectosigmoid endometriosis. CTC and RWC-TVS had similar accuracy in the diagnosis of rectosigmoid endometriosis (P = 0.508) and similar precision in estimating the length of the endometriotic nodules (P = 0.077). CTC was more precise than RWC-TVS in estimating the distance between the rectosigmoid nodule and the anal verge (P < 0.001). The intensity of pain experienced during CTC was higher than that perceived during RWC-TVS (P < 0.001); however, intestinal distension for CTC was well-tolerated in all patients without significant adverse effects. CONCLUSIONS: RWC-TVS and CTC have similar accuracy in the diagnosis of rectosigmoid endometriosis and similar precision in estimating the size of the nodules; however, CTC is more precise than RWC-TVS in estimating the distance between the nodules and the anal verge, yet patients tolerate RWC-TVS better than CTC.