目的　了解经肛门超声内镜检查对内口已经愈合的肛瘘病人内口部位的诊断价值。方法　对临床常规手术未能发现肛瘘内口的 12例病人进行超声内镜检查 ,并进行手术治疗。分析经肛门超声内镜检查对内口已经愈合的肛瘘病人内口部位的诊断价值和超声影像学特点 ,并与其它常规检查方法比较。结果　内镜超声检查在 12例病人均发现已经愈合的内口的准确位置 ,准确性优于Goodsall规律、肛门直肠肛门指诊、窦道造影或美蓝注射以及窦道探针探查。结论　经肛瘘外口位置注射美蓝 ,可方便手术医师快速定位内口。经肛门超声内镜检查是定位已经愈合的肛瘘内口的准确、快速、简单、耐受性好的检查手段。在超声内镜发现内口后 ,经内镜在内口位置注射美蓝 ,可方便手术医师快速定位内口 Objective To understand the diagnostic value of the internal ostia of anal fistula patients who have healed by transanal endoscopic ultrasonography. Methods Twelve patients who failed to find the internal fistula in clinical routine surgery underwent endoscopic ultrasonography and were operated on. To analyze the diagnostic value and ultrasound imaging features of anal fistula patients who had healed by transanal endoscopic ultrasonography, and to compare with other routine examination methods. Results Endoscopic ultrasonography found that the exact position of the internal mouth that had healed was superior to that of Goodsall’s rule, anus and anus, sinusography or methylene blue injection, and sinus probe exploration in all 12 patients. Conclusion Anal fistula outside the mouth position injection of methylene blue, can facilitate the surgeon to quickly locate the mouth. Transanal endoscopic ultrasonography is an accurate, rapid, simple and well-tolerated method of testing the location of an internal anal fistula that has healed. Endoscopic ultrasound found in the mouth, the endoscopic injection of methylene blue endometrial position, the surgeon can facilitate the rapid positioning of the mouth