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Daniel Moritz Felsenreich
Priv. Doz. DDr. Daniel Moritz Felsenreich

Department of General Surgery (Division of Visceral Surgery)
Position: Research Associate (Postdoc)

ORCID: 0000-0002-5229-5096
T +43 1 40400 56220


Anastomosis, Roux-en-Y; Bariatric Medicine; Bariatric Surgery; Bariatrics; Bile Reflux; Gastric Bypass; Gastroesophageal Reflux

Research interests

As a member of Univ. Doz. Dr. Gerhard Prager’s team for metabolic and bariatric surgery I have specialized in doing research on Sleeve Gastrectomy, One-Anastomosis Gastric Bypass, as well as the treatment of weight regain after Roux-en-Y gastric bypass. My long-term study of Sleeve gastrectomy focusses reflux, weight regain, and quality of life. With my ongoing RCT on One-Anastomosis Gastric Bypass I aim at revealing the impact of anti-reflux sutures on biliary reflux after the procedure. I am also studying the outcome of different methods of treating weight regain (e.g. pouch resizing and banding) after Roux-en-Y gastric bypass.

Techniques, methods & infrastructure

  • Retrospective database analyses
  • Prospective clinical trials


Selected publications

  1. Felsenreich, D.M. et al. (2022) ‘Fifteen Years after Sleeve Gastrectomy: Gastroscopies, Manometries, and 24-h pH-Metries in a Long-Term Follow-Up: A Multicenter Study’, Obesity Facts, pp. 1–8. Available at:
  2. Felsenreich, D.M. et al. (2022) ‘Outcome of Sleeve Gastrectomy Converted to Roux-en-Y Gastric Bypass and One-Anastomosis Gastric Bypass’, Obesity Surgery, 32(3), pp. 643–651. Available at:
  3. Felsenreich, D.M. et al. (2020) ‘Meta-analysis of Postoperative Mortality and Morbidity After Total Abdominal Colectomy Versus Loop Ileostomy With Colonic Lavage for Fulminant Clostridium Difficile Colitis’, Diseases of the Colon & Rectum, 63(9), pp. 1317–1326. Available at:
  4. Felsenreich, D.M. et al., 2018. Update: 10 Years of Sleeve Gastrectomy—the First 103 Patients. Obesity Surgery, 28(11), pp.3586–3594. Available at:
  5. Felsenreich, D.M. et al., 2019. Roux-en-Y Gastric Bypass as a Treatment for Barrett’sEsophagus after Sleeve Gastrectomy. Obesity Surgery. Available at: