BackgroundRoux-en-Y gastric bypass (RYGB) is the most common bariatric procedure worldwide. Anastomotic stricture is a known complication of RYGB. The aim was to explore the incidence and outcomes of strictures within the Scandinavian Obesity Surgery Registry (SOReg).MethodSOReg included prospective data from 36,362 patients undergoing bariatric surgery in the years 2007-2013. Outcomes were recorded at 30-day and at 1-year follow-up according to the standard SOReg routine. The medical charts of patients suffering from stricture after RYGB were requested and assessed.SettingNational bariatric surgery registryResultsAnastomotic stricture within 1year of surgery was confirmed in 101 patients representing an incidence of 0.3%. Risk factors for stricture were patient age above 60years (odds ratio (OR), 6.2 95% confidence interval (CI) 2.7-14.3), circular stapled gastrojejunostomy (OR 2.7, 95% CI 1.4-5.5), postoperative anastomotic leak (OR 8.9 95%, CI 4.7-17.0), and marginal ulcer (OR 30.0, 95% CI 19.2-47.0). Seventy-five percent of the strictures were diagnosed within 70days of surgery. Two dilatations or less was sufficient to successfully treat 50% of patients. Ten pecent of patients developed perforation during dilatation, and the risk of perforating at each dilatation was 3.8%. Perforation required surgery in six cases but there was no mortality. Strictures in SOReg may be underreported, which could explain the low incidence in the study.ConclusionMost strictures present within 2months and are successfully treated with two dilatations or less. Dilating a strictured gastrojejunostomy entails a risk of perforation (3.8%).