Abstract: Objective The aim of this study was to investigate the application and clinical value of ultra-fine nasal endoscopy in the diagnosis and treatment of digestive tract stenosis. Methods A retrospectively investigation of 160 cases of nasogastricoscopy in esophageal, gastroduodenal and colorectal stenosis lesions, the detection rate of lesions under the stenosis and endoscopic treatment were analyzed from January 1, 2016 to December 31, 2017. Results In 102 cases of diagnostic examination, the passing rates of nasogastricoscopy in esophageal, gastroduodenum and colorectal stenosis were 76.92%, 50.00% and 88.00%, respectively.In the cases which the endoscope could successfully pass the stenotic lesions, the detection rates of new lesions below the stenosis were 8.89%, 0 and 27.78%, respectively, in esophageal, gastroduodenum and colorectal stenosis.A total of 58 cases of digestive tract stenosis were treated with endoscopic gastroscopy.Among them, 46 cases had stenosis and the pass rate was 79.31%. Conclusion Ultra-fine nasal endoscopy can significantly improve the completeness and accuracy of endoscopic diagnosis in patients with digestive tract stenosis that cannot be passed by standard gastrointestinal endoscopy.It can also be used for endoscopic treatment of digestive tract stenosis.

Key words: Transnasal endoscopy, Ultra-fine, Digestive tract stenosis, Endoscopic diagnosis, Endoscopic treatment