Objective To investigate the value of endoscopic retrograde appendicitis therapy(ERAT)in the diagnosis and treatment of appendiceal diseases(appendix fecalith and acute uncomplicated appendicitis).Methods Twenty patients with the diagnosis of appendix fecalith or uncomplicated acute appendicitis who underwent colonoscopy or ERAT from January 2020 to December 2022 were included in this study.Mean operative time,imaging findings and colonoscopy findings,rate of complication and rate of appendectomy during follow-up period were retrospectively reviewed.Results The patients ranged in age from 14 to 65 years.The duration of abdominal pain ranged from 4 hours to 6 years.Acute appendicitis was diagnosed in 11 patients with mucosal inflammation at the appendix opening during ERAT treatment.Abdominal pain relieve immediately after ERAT treatment,and 1 patient accepted laparoscopic appendectomy during follow-up.1 of them was diagnosed with colitis.8 patients showed mucosal inflammation or maturation at the appendix opening accepted ERAT,and removed fecalith,and their abdominal pain was relieved after surgery.Stone basket was used in two patients during extraction of fecalith.During follow-up period,only 1 patient underwent appendectomy,and the postoperative pathology showed chronic appendicitis.Conclusion ERAT is a safe and effective method to diagnose and treat acute uncomplicated appendicitis and appendix fecalith.