- Weight loss can be comparable (Vitalys).
- Bypass: first choice with type 2 diabetes and reflux.
- Sleeve: with adhesions, BMI above 60 or bowel disease.
- Sleeve can worsen reflux; bypass can cause dumping.
- The final choice is made with the team after screening.
What is the difference between a sleeve and a bypass?
A sleeve removes about three quarters of the stomach and leaves the intestine alone. A bypass creates a small stomach pouch and reroutes food past the first part of the small intestine. The rerouting changes gut hormones more strongly, which is why a bypass has more effect on blood sugar and reflux, and also why deficiencies and dumping are more common.
Vitalys explains that all Dutch centres choose the bypass more often because of their experience with it, while both operations can lead to roughly similar weight loss.
Three situations in which a sleeve is preferred
Vitalys names three: many adhesions in the abdomen after earlier operations, a BMI above 60, and intestinal diseases such as Crohn's disease or ulcerative colitis. With a BMI above 60 the sleeve is often a first step, with a SADI possible about two years later.
Where does the mini gastric bypass fit in?
The mini bypass is technically somewhat simpler than the classic bypass, with one connection. According to WeightWorks, there are no differences in outcomes between the two after twenty years. Bile reflux is slightly more common after a mini bypass, internal hernias much less.
If you are unsure, ask the centre about its experience with each procedure. The final choice is made together with the surgeon after screening.
Strengths of each operation
Advantages
| Advantage | Explanation |
|---|---|
| Bypass: diabetes | blood sugar often improves within days |
| Bypass: reflux | usually decreases |
| Sleeve: intestine intact | less malabsorption |
| Sleeve: shorter operation | about 45-75 minutes |
Points of attention
| Point of attention | Explanation |
|---|---|
| Bypass: dumping | after sugar and fat |
| Bypass: internal hernia | about 1-1.5% |
| Sleeve: reflux | can increase |
| Sleeve: irreversible | part of the stomach removed |
Cost and insurance (2026)
Coverage is identical: both are standard operations in the Dutch basic package.
| Item | Amount or arrangement |
|---|---|
| Sleeve or bypass (covered) | €385 deductible (2026) |
| Self-pay range | roughly €7,000 to €11,000 |
| Calcium per day | sleeve at least 1,000 mg, bypass at least 1,500 mg |
Sleeve or bypass: key figures
| Feature | Value |
|---|---|
| Weight loss sleeve | about 20-30% of total body weight |
| Weight loss bypass | about 30-40% of total body weight |
| Operation time sleeve | 45-75 minutes |
| Operation time bypass | 90-120 minutes |
| Mini bypass vs bypass after 20 years | no differences (WeightWorks) |
Sleeve versus bypass in one table
| Feature | Gastric sleeve | Gastric bypass |
|---|---|---|
| Intestine rerouted | no | yes |
| Type 2 diabetes | good effect | strongest effect |
| Reflux | can increase | usually decreases |
| Dumping | rare | common |
| Reversible | no | technically possible |
Step by step
- Your situation. Diabetes, reflux, earlier surgery, BMI.
- Information. Compare both operations.
- Screening. The team assesses what fits.
- Decision. Together with the surgeon.
- Operation. Keyhole surgery at a DATO centre.
Read next
- Gastric sleeve in detail — results and risks
- Gastric bypass in detail — results and drawbacks
- Mini gastric bypass — one connection
- Types of weight loss surgery — all options
Questions to ask your surgeon
Which procedure does the centre perform most often, and why do you recommend this one for me? How do my reflux, diabetes or earlier abdominal operations influence the choice? What is the plan if I develop reflux after a sleeve, or regain weight after a bypass?
Also ask about the practical side: how long is the hospital stay, which vitamins will I need, and which parts of the follow-up are available in English? Writing your questions down before the appointment helps you get complete answers.
Bring a list of your medication as well.
Ask whether you can meet the surgeon who will actually perform your operation.
What if you and the team disagree?
Your preference counts, but the final choice is medical. If the team advises against the operation you prefer, ask for the reasons in writing. You can discuss them with your GP or, if needed, ask for a second opinion at another DATO-certified centre.
A second opinion is a normal part of Dutch healthcare and does not affect your coverage, as long as the centre is contracted by your insurer.
Frequently asked questions: sleeve or bypass
Neither is better for everyone. Weight loss can be comparable. A bypass is usually better with type 2 diabetes or reflux; a sleeve with many adhesions, a BMI above 60 or bowel disease.
The gastric bypass, mainly because Dutch centres have the most experience with it, according to Vitalys.
On average the bypass gives slightly more, roughly 30 to 40 percent of total body weight against 20 to 30 percent after a sleeve, but individual results vary widely.
Both have a favourable risk profile. Nationally, 1.4 percent of Dutch patients had a serious complication in 2024. The specific risks differ: reflux and irreversibility for the sleeve, dumping and internal hernia for the bypass.
Usually the bypass, because it tends to reduce reflux, while a sleeve can make it worse. Always mention reflux during screening.
The bypass is the first choice with type 2 diabetes according to Vitalys, provided the rest of your medical history allows it.
Yes, through revision surgery, often because of reflux. It is a new operation with a new screening.
Both need a WLS multivitamin suited to the operation. Calcium: at least 1,000 mg a day after a sleeve and at least 1,500 mg after a bypass.
It is a full bypass with one connection instead of two. Results are comparable to the classic bypass after twenty years, with fewer internal hernias but slightly more bile reflux.
You and the surgeon together, after screening. Your preferences count, but medical factors weigh heavily.
Call +31 6 38048347 (Mon–Fri 09:00–17:00) or email info@maagverkleining-info.nl. This page is also available in Dutch.
Sources
- Vitalys (Rijnstate): sleeve or bypass
- WeightWorks: mini gastric bypass and gastric bypass
- DATO Annual Report 2024, DICA
Search terms leading here: gastric sleeve or gastric bypass, sleeve vs bypass Netherlands, which weight loss surgery is best, bypass or sleeve reflux.
Author: Gijs Bodenstaff. Last reviewed: September 2026.