Key points
- Surgery generally leads to significant, lasting weight loss and often improves obesity-related conditions.
- Serious complications are uncommon in recognised centres, but they do occur, including years later.
- Some constraints last for life: supplements, blood tests and follow-up.
What surgery can offer
In carefully selected people, the Swiss guidelines report significant, lasting weight loss and an improvement in obesity-related conditions, such as type 2 diabetes1. The specific features of each technique are described on the Gastric bypass and Sleeve gastrectomy pages. The expected benefits are discussed with you according to your situation and your goals.
Risks around the time of the operation
In certified centres, the Swiss guidelines report severe short-term complications in 1 to 3% of people who have the operation, and a death rate of 0.05 to 0.20%1.
The main early complications are bleeding, a leak at a suture line, infection, thrombosis or embolism. They are monitored during your hospital stay and in the following weeks: Hospital stay and return home.
Longer-term risks
During follow-up, a further operation is sometimes needed, for example for an internal hernia, an ulcer or a narrowing1. This risk depends on the technique and is a reason for regular follow-up.
Without supplements, vitamin and mineral deficiencies can develop without any symptoms. Psychological support can be offered to help you cope with the changes after the operation. Particular care is also needed with alcohol.
Lifelong constraints
- taking vitamins and minerals every day1;
- attending check-ups: at the Centre, they are frequent in the first year, then every six months from the second year onwards, for life;
- permanently adapting the way you eat: small amounts, slow meals;
- planning any future pregnancy with the team;
- telling any doctor about your operation, especially before starting new medicines.
Details are given on the Life and follow-up after surgery page.
What about other options?
Surgery is not the only route. Medical support and, in some situations, medication can be offered instead, before or after. Choosing not to have surgery is also a legitimate decision; it does not prevent follow-up at the Centre.
Frequently asked questions
How are the benefits and risks assessed in my case?
During the assessment, several professionals review your situation: your health, your treatments, the operation being considered and your goals. Benefits and risks are discussed with you, and the decision is made collectively by the multidisciplinary team, taking your wishes into account.
What happens if there is a complication?
Complications are preferably managed by the centre that performed the operation, or after seeking its advice2. Useful contacts are listed on the Hospital stay page.
What next?
If this page sounds like your situation, you can book a surgical assessment consultation. Its purpose is to review your situation and the possible options; any operation is then decided collectively by the multidisciplinary team, with you.
Your request is received by the Centre’s appointments team, who will organise the next steps with you. You do not need to check for yourself whether you meet the criteria.
Medical review of the French version: Dr Pierre Fournier
Scientific sources and references
Sources accessed on 12 October 2026. Reimbursement rules and information on medicines change over time.
- Gerber PA, Collet TH, Favre L, et al. Swiss obesity clinical practice guidance. Swiss Med Wkly. 2026;156:5415. View source
- IFSO-EC, version adopted by the SMOB. La prise en charge en urgence du patient opéré de chirurgie métabolique et bariatrique (poster for emergency departments), 2026. View source
- Author
- Prepared for the Centre from the sources cited
- References
- See “Scientific sources and references” on this page