Gastric Bypass Surgery
Gastric bypass creates a small pouch from the upper part of the stomach and connects it directly to the small intestine. Because it alters both the amount of food taken in and the hormonal arrangement of the digestive tract, its metabolic effect is pronounced.
When gastric bypass comes to the fore
- In patients with obesity and significant reflux, since the operation generally reduces reflux.
- In long-standing or insulin-treated type 2 diabetes, because of its metabolic effect.
- As a revision option for patients who have had a sleeve gastrectomy without an adequate result.
- No stomach tissue is removed; the digestive tract is rearranged, so reversal is possible in some situations.
- Vitamin and mineral absorption is reduced, so lifelong supplementation and blood monitoring are required.
How the operation is performed
A small pouch of roughly 30–50 ml is separated from the upper part of the stomach, close to the oesophagus. The small intestine is divided at a set distance and its lower end is joined directly to this pouch. The other end is reconnected further down so that bile and pancreatic juices can meet the food.
Food therefore bypasses the greater part of the stomach and the duodenum. The operation is carried out by the keyhole method, laparoscopically or robotically.
Effect on type 2 diabetes
The effect of gastric bypass on blood sugar is not due to weight loss alone. Food reaching the lower small intestine early alters the release of incretin hormones that regulate insulin secretion. In some patients this effect appears before weight loss becomes apparent.
The duration of diabetes, the pancreas's remaining capacity to produce insulin and the history of insulin use are the main factors determining the benefit expected from surgery.
Points to consider
- Dumping syndrome: palpitations, sweating, weakness and diarrhoea can follow sugary or rapidly absorbed foods. This is managed through diet.
- Vitamin deficiencies: B12, iron, folate, calcium and vitamin D levels must be monitored regularly.
- Endoscopic access: reaching the bypassed part of the stomach with standard endoscopy becomes difficult, which is weighed in the decision for people at higher risk of gastric disease.
Key facts
| Operating time | About 1.5–2.5 hours |
|---|---|
| Anaesthesia | General anaesthesia |
| Method | Laparoscopic or robotic |
| Hospital stay | Usually 3–4 days |
| Supplements | B12, iron, calcium, vitamin D — lifelong |
| Return to daily life | About 3 weeks |
Frequently asked questions
Which is better, gastric bypass or sleeve gastrectomy?
Each is superior in different circumstances. Bypass comes to the fore in reflux and long-standing type 2 diabetes, while sleeve gastrectomy may be preferred when a shorter operation without malabsorption is the goal. The decision is individual.
Can gastric bypass be reversed?
Technically the connections can be restored, but this is a second major operation and is rarely needed. The procedure is planned as a permanent treatment.
Will I continue my medication afterwards?
Doses of diabetes and blood pressure medication are adjusted by your doctor according to your blood results after surgery. Do not stop any medication on your own.
Can I drink alcohol after gastric bypass?
Alcohol is absorbed faster and felt more strongly, and the empty calories work against weight loss. Avoiding alcohol, particularly in the first year, is advised.
The information on this page is for general guidance only and does not replace a consultation. The treatment that suits you can only be determined after examination and tests.
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