Bariatric surgery
A guide to bariatric surgery
From sleeve gastrectomy and bypass to preoperative assessment and long-term follow-up: information for an informed decision.
Educational adaptation of an article from the previous website • Content updated: 27 September 2026
What does bariatric surgery do?
Metabolic and bariatric surgery helps weight loss by changing digestive anatomy and signals involved in appetite and metabolism. It is suitable for some people with obesity and related conditions, but does not completely replace nutrition, physical activity or medical follow-up.
How do sleeve and bypass differ?
Sleeve gastrectomy removes a large part of the stomach without changing the intestinal route. Bypass creates a small stomach pouch and changes the route food takes. Reflux, diabetes, previous surgery, eating patterns and the risk of nutritional deficiencies affect the choice. No procedure is best for everyone.
What assessment is needed before surgery?
Assessment usually covers associated conditions, medicines, nutrition, mental health and readiness for long-term care. Tests and further investigations depend on individual circumstances. Discuss sleep apnoea, previous blood clots, smoking and pregnancy plans with your team.
What results are realistic?
The amount and pace of weight loss depend on the procedure and the individual. Diabetes, high blood pressure or sleep apnoea may improve, but improvement is not guaranteed. Some weight regain is possible and may require nutritional assessment, medication or additional treatment; keep attending follow-up.
Risks and responsibilities after surgery
Bleeding, leaks, infection and blood clots are possible early risks. Reflux, digestive problems and micronutrient deficiencies may occur later. Before discharge, obtain your supplement plan, schedule for blood tests and emergency contact pathway. Check current costs and insurance coverage with the relevant centre.
This article provides general information. Treatment and nutrition plans must fit your procedure, associated conditions and individual circumstances.
Sources and article history
Adapted and rewritten from an older article. Absolute claims, outdated prices and advice needing correction have not been republished unchanged.