Glossary term · Treatment
Gastric bypass (also: Roux-en-Y gastric bypass, RYGB): Gastric bypass is a weight-loss operation that creates a small stomach pouch and connects it to the small intestine, bypassing most of the stomach.
Gastric bypass is weight-loss surgery that divides the stomach into a small upper pouch and connects it directly to a lower part of the small intestine. MedlinePlus explains that food then skips most of the stomach and part of the intestine. You feel full sooner and absorb fewer calories. The common form is called Roux-en-Y.
How is it done?
MedlinePlus says staples divide the stomach into a small upper pouch and a larger lower section. A section of the small intestine called the jejunum is joined to the pouch. The operation can be open or laparoscopic through several small cuts. NIDDK notes it is difficult to reverse.
Who may be considered?
MedlinePlus says candidates typically have a BMI of 35 or higher, or 30 to 34.9 with a serious condition such as type 2 diabetes or sleep apnoea. The threshold is lower, 27.5, for people of Asian descent. Candidates have usually not lost enough weight with diet, exercise and medicines. The bariatric team decides who is suitable.
What risks are specific to bypass?
- Dumping syndrome, when food moves too quickly into the small intestine, often after starchy or sugary meals.
- Poor nutrition, because part of the intestine is bypassed.
- Ulcers and leaks at the staple line.
- Bowel blockage from scarring.
- Vomiting if the pouch is overfilled.
NIDDK says lifelong vitamin and mineral supplements are needed after bypass.
What should travelling patients plan for?
MedlinePlus describes a staged return to eating: no food at first, then liquids, then puréed or soft food. Discharge depends on tolerating this without vomiting. Before you fly home, make sure you have written diet stages, a supplement list and a doctor or dietitian at home who will arrange regular blood tests. Your surgeon decides when it is safe to travel.
Questions people ask
What is the difference between a bypass and a sleeve?
A sleeve removes most of the stomach but keeps the normal food route. A bypass creates a small pouch and reroutes the intestine, which also reduces absorption. MedlinePlus notes nutrition problems are more likely after a bypass. Your surgeon advises which suits you.
Is a mini gastric bypass the same operation?
No. The mini gastric bypass is a different technique with one intestinal connection. It is described separately in our procedure guide. Ask your surgeon which type they propose and why.
Sources
General information, not medical or legal advice. Rules change: confirm with the official source. Your treating specialist decides on suitability, treatment and length of stay. How we write and check.