Dumping syndrome is a long-term postoperative complication of Roux-en-Y gastric bypass procedures. Morphologically, dumping syndrome usually correlates with a dilatation of the gastroenterostomy with accelerated pouch emptying. Conservative therapy includes diet changes, complementary pharmacotherapy and, if symptoms persist, surgical revision. Surgical options include endoscopic, endoluminal surgery to constrict the gastrojejunostomy using a novel endoscopic suturing device (OverStitch(TM), Apollo). In our study, we aimed to assess the viability, safety and efficacy of this procedure in patients with late dumping; 14 patients who had developed late dumping syndrome underwent surgery using an endoscopic suturing technique (OverStitch(TM), Apollo). Late dumping was confirmed by Sigstad score and an oral glucose tolerance test (OGTT). Prior to surgery, objective analysis of pouch emptying speed was assessed by gastric scintigraphy. Surgery was performed under general anaesthesia. None of the 14 patients suffered intra- or postoperative complications. No postsurgical increase in inflammation parameters was observed. The postinterventional pain scale (visual analogue scale) showed a mean score of 0.5 (range 0-10). In 13 of the 14 patients, no dumping was observed 1-month postsurgery. The postoperative Sigstad score (3.07 ± 2.06; range 1-9) showed an impressive reduction compared with the preoperative score (12.71 ± 4.18; range 7-24) (p < 0.001). Postoperative upper gastrointestinal gastrografin swallow revealed regular emptying in all the patients. The endoluminal endoscopic suturing technique-applied here for surgical revision of gastroenterostomy following Roux-en-Y gastric bypass-represents a promising, novel therapeutic option in late dumping syndrome involving minimal trauma and offering rapid reconvalescence.