# Roux-en-Y Gastric Bypass > Citation bundle for Roux-en-Y Gastric Bypass on The Treatment Registry. > URL: https://thetreatmentregistry.com/procedures/gastric-bypass > Bundle URL: https://thetreatmentregistry.com/api/citations/procedures/gastric-bypass - Category: weight-loss - Average recovery: 21 days - Typical sessions: 1 - Price range (USD international): $11,000–$26,000 ## Description Roux-en-Y gastric bypass is a bariatric surgery that creates a small gastric pouch (typically 15-30ml) and bypasses most of the stomach and proximal small intestine. The procedure has two mechanisms: restriction (small pouch reduces meal volume) and malabsorption (bypassed proximal small bowel reduces nutrient absorption). RYGB produces typically greater weight loss than sleeve gastrectomy in many series, better resolution of type 2 diabetes and reflux disease, and a more durable long-term result — at the cost of technical complexity, higher early-complication rate, more demanding lifelong nutritional supplementation, and a small ongoing risk of internal hernia. ## Overview Roux-en-Y gastric bypass is the most established form of gastric bypass surgery, a technique in which the stomach is divided into a small upper pouch and a much larger lower 'remnant' pouch, and the small intestine is rearranged to connect to both. This markedly reduces the functional volume of the stomach and alters the body's physiological and physical response to food, producing weight loss through both restriction and reduced nutrient absorption. It is indicated for severe obesity — generally a body mass index above 40, or above 35 with a related comorbid condition such as type 2 diabetes, hypertension or obstructive sleep apnoea — and is usually offered only after diet and lifestyle efforts have not achieved sustained weight loss. Guidelines from the 1991 NIH consensus panel set these criteria and emphasised multidisciplinary care by a team of physicians and therapists. Weight loss of 65–80% of excess body weight is typical across large reported series, and comorbidities often improve substantially: hyperlipidaemia is corrected in over 70% of patients, hypertension is relieved in over 70%, obstructive sleep apnoea improves markedly, gastro-oesophageal reflux is relieved in almost all patients, and type 2 diabetes is reversed in up to 90%. Long-term mortality has been shown to fall by up to 40%. As with any major operation complications can occur; one 2005–2006 study found that 15% of patients experienced complications and 0.5% died within six months of surgery. ## Peer-reviewed outcome rates - **Complication rate:** 8.00% (range 5.00–12.00%) — from 2 cited sources - **Revision rate:** 7.00% (range 3.00–12.00%) — from 1 cited source - **Mortality rate:** 0.30% (range 0.10–0.50%) — from 1 cited source ## Common risks - Anastomotic leak - Bleeding - Internal hernia - Marginal ulcer - Stricture at gastrojejunostomy - Nutritional deficiencies - Dumping syndrome ## FAQs ### RYGB vs sleeve gastrectomy — which is right for me? RYGB is typically preferred for patients with severe reflux, Barrett's oesophagus, or strong metabolic indications (severe type 2 diabetes). Sleeve is typically preferred for patients without those indications, particularly first-time bariatric patients seeking a simpler, technically lower-risk procedure. A multidisciplinary team decision is standard. ### How much weight will I lose? Typical excess weight loss at 2 years after RYGB is 65-80%. Sustained weight loss at 10 years is 50-65%. Individual variation is substantial — long-term success correlates strongly with adherence to dietary and lifestyle change after the procedure. ### What is dumping syndrome? Dumping syndrome occurs when high-sugar food enters the small bowel rapidly through the small gastric pouch. Symptoms include nausea, sweating, palpitations, abdominal cramping, and weakness, usually 15-30 minutes after eating. It is largely preventable by avoiding concentrated sweets and following dietary guidance. ### Will I need vitamins for life? Yes — lifelong supplementation with B12, iron, calcium, vitamin D, and a multivitamin is universal advice after RYGB because the bypassed proximal small bowel is where most micronutrient absorption occurs. Annual surveillance bloods are essential. ### What is an internal hernia? An internal hernia is a complication unique to bypass procedures: small bowel can twist through one of the mesenteric defects created during surgery, causing obstruction. Rates have fallen with the widespread practice of mesenteric defect closure but remain a lifetime risk (1-5%). Symptoms include new-onset cramping abdominal pain, particularly after meals. ### Can RYGB be reversed? Technically yes, but reversal is a major operation rarely performed and rarely indicated. RYGB should be considered a permanent decision. ### Can I have gastric bypass if I have had previous abdominal surgery? Previous abdominal surgery is not a contraindication but can make laparoscopic access more challenging due to adhesions. The surgeon may convert to open surgery intra-operatively if safe laparoscopic access is not feasible. Pre-operative imaging to map any anticipated adhesions is sometimes performed. ### Will gastric bypass affect medication absorption? Yes — bypass alters the absorption of some medications because the proximal small bowel (the main absorption site for many oral drugs) is bypassed. Extended-release formulations are commonly switched to immediate-release equivalents. Certain medications (e.g. some antifungals, thyroid hormone) may require dose adjustment based on serum-level monitoring. ## Alternative treatments - **Gastric sleeve** — Simpler procedure with fewer nutritional risks; slightly less long-term weight loss. - **Duodenal switch** — Greatest weight loss + diabetes remission, highest nutritional-deficiency risk. - **SADI-S** — Single-anastomosis duodenal switch; near-equivalent weight loss with lower complication rate. - **GLP-1 receptor agonists** — Pharmacological route now achieving meaningful weight loss; combination therapy may be appropriate. ## Sources - [Cochrane Database — Surgery for weight loss in adults](https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD003641.pub5/full) — Cochrane Database of Systematic Reviews (accessed 2026-05-09) - [IFSO — Clinical Guidelines for Bariatric and Metabolic Surgery](https://www.ifso.com/clinical-guidelines/) — International Federation for the Surgery of Obesity and Metabolic Disorders (accessed 2026-05-09) - [ASMBS — Clinical Practice Guidelines for Metabolic and Bariatric Surgery](https://asmbs.org/resources/clinical-practice-guidelines) — American Society for Metabolic and Bariatric Surgery (accessed 2026-06-29) - [NICE NG89 — Venous thromboembolism in over 16s: reducing the risk of hospital-acquired DVT and PE](https://www.nice.org.uk/guidance/ng89) — National Institute for Health and Care Excellence (accessed 2026-05-09)