# Mini Gastric Bypass > Citation bundle for Mini Gastric Bypass on The Treatment Registry. > URL: https://thetreatmentregistry.com/procedures/mini-gastric-bypass > Bundle URL: https://thetreatmentregistry.com/api/citations/procedures/mini-gastric-bypass - Category: weight-loss ## Description Gastric bypass surgery refers to a technique in which the stomach is divided into a small upper pouch and a much larger lower "remnant" pouch, where the small intestine is rearranged to connect to both. Surgeons have developed several different ways to reconnect the intestine, thus leading to several different gastric bypass procedures (GBP). ## Overview Mini gastric bypass is one of the gastric bypass procedures. Gastric bypass surgery refers to a technique in which the stomach is divided into a small upper pouch and a much larger lower 'remnant' pouch, with the small intestine rearranged to connect to both; surgeons have developed several different ways to reconnect the intestine, leading to several different gastric bypass procedures. Any gastric bypass produces a marked reduction in the functional volume of the stomach, together with an altered physiological and physical response to food, and this underlies the weight loss that follows. The operation is prescribed for severe obesity — defined as a body mass index above 40, or above 35 with a related comorbid condition — and to treat associated conditions such as type 2 diabetes, hypertension and obstructive sleep apnoea. It is generally considered only after diet and lifestyle measures have not produced satisfactory, sustained weight loss, and it requires multidisciplinary assessment and follow-up. Across large reported series of gastric bypass operations, weight loss of 65–80% of excess body weight is typical, and comorbid conditions frequently improve. As with all major abdominal surgery, complications can occur; reported figures include a complication rate of about 15% in one 2005–2006 study, with overall 30-day complication rates ranging from 7% for laparoscopic procedures to 14.5% for open operations. ## Peer-reviewed outcome rates - **Mortality rate:** 0.72% (range 0.53–0.90%) — from 2 cited sources ## FAQs ### What is a mini gastric bypass? It is one of the gastric bypass procedures. In a gastric bypass 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. Surgeons have developed several different ways to reconnect the intestine, which is why more than one type of gastric bypass exists. ### How does gastric bypass lead to weight loss? Any gastric bypass produces a marked reduction in the functional volume of the stomach, accompanied by an altered physiological and physical response to food. Together these changes reduce how much can be eaten and how the body handles what is eaten, resulting in weight loss. ### Who is a candidate for the procedure? Gastric bypass is prescribed for severe obesity, generally a body mass index above 40, or above 35 with a related comorbid condition. It is usually considered only after diet and lifestyle efforts have not produced satisfactory and sustained weight loss. ### What conditions can it help besides excess weight? It is used to treat obesity-related conditions including type 2 diabetes, hypertension and obstructive sleep apnoea. Across reported series, comorbid conditions frequently improve following the resulting weight loss. ### How much weight is typically lost? Weight loss of 65–80% of excess body weight is typical of most large series of gastric bypass operations that have been reported. Individual results vary and depend on follow-up and adherence to dietary guidance. ### What are the risks? As with all major abdominal surgery, complications can occur. One 2005–2006 study reported a complication rate of about 15%, and overall 30-day complication rates have ranged from 7% for laparoscopic procedures to 14.5% for open operations. Complications include infection of the incisions or the abdomen and other events common to major abdominal surgery. ## Alternative treatments - **Roux-en-Y gastric bypass** — Classical two-anastomosis bypass; better-studied long-term outcomes. - **Gastric sleeve** — Simpler restrictive-only procedure; comparable initial weight loss. ## Cited authors - S Chiappetta — Klinik für Adipositas- und Metabolische Chirurgie, Sana Klinikum Offenbach, Starkenburgring 66, 63069, Offenbach am Main, Deutschland. so… - Chetan D Parmar — The Whittington Hospital, Magdala Avenue, London, N19 5NF, UK. cparmar@nhs.net. ## Sources - [One Anastomosis (Mini) Gastric Bypass Is Now an Established Bariatric Procedure: a Systematic Review of 12,807 Patients.](https://doi.org/10.1007/s11695-018-3382-x) — Obesity surgery (accessed 2026-07-13) - [[Evidence of the Mini-/One-anastomosis-gastric-Bypass for being a standard procedure in obesity and metabolic surgery].](https://doi.org/10.1007/s00104-018-0663-9) — Der Chirurg; Zeitschrift fur alle Gebiete der operativen Medizen (accessed 2026-07-13) - [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)