- Long stomach tube with one connection to the small intestine.
- Operation time about 60-90 minutes.
- Internal hernia below 0.12% (WeightWorks).
- Slightly more bile reflux than the classic bypass.
- Covered by Dutch basic insurance with a valid indication.
What is a mini gastric bypass?
In a mini gastric bypass the surgeon staples the stomach into a long tube and connects the end of that tube to a loop of small intestine further down. Food bypasses the first part of the small intestine, which reduces absorption and changes gut hormones, just like in a classic bypass. Because there is only one connection, the operation usually takes 60 to 90 minutes.
WeightWorks reports that after twenty years there are no differences in outcomes between the mini and the classic bypass. The mini bypass is therefore a standard operation under the Dutch guideline, not an experimental alternative.
What is bile reflux and why does it matter here?
With a single connection, bile and pancreatic juice pass the stomach tube through the same loop. Sometimes bile flows back upwards, causing a bitter taste or burning feeling. It is usually treatable with medication; in persistent cases the mini bypass can be converted to a classic bypass. Existing severe reflux can be a reason for the team to choose a classic bypass instead.
Who is the mini gastric bypass suitable for?
It is an option for the same group as the classic bypass: a BMI of 40 or higher, or 35 or higher with a weight-related condition. The team may prefer it when a shorter operation is desirable or when the anatomy makes a classic bypass harder.
Because fat is absorbed less well, the fat-soluble vitamins A, D, E and K need extra attention. You take a WLS multivitamin suited to the mini bypass and at least 1,500 mg of calcium with vitamin D a day, for life.
Advantages and points of attention: mini gastric bypass
Advantages
| Advantage | Explanation |
|---|---|
| One connection | technically somewhat simpler |
| Shorter operation | about 60-90 minutes |
| Few internal hernias | below 0.12% (WeightWorks) |
| Comparable results | no differences after 20 years (WeightWorks) |
Points of attention
| Point of attention | Explanation |
|---|---|
| Bile reflux | slightly more common than after a classic bypass |
| Fat-soluble vitamins | A, D, E and K need extra attention |
| Lifelong supplements | WLS multivitamin and 1,500 mg calcium |
| No NSAIDs | risk of an ulcer at the connection |
Cost and insurance (2026)
The mini bypass falls under the same coverage rules as the other standard operations.
| Item | Amount or arrangement |
|---|---|
| Covered pathway | €385 deductible (2026) |
| Self-pay range | roughly €7,000 to €11,000 |
| Vitamins and calcium | about €10-€15 a month |
Mini gastric bypass: key figures
| Feature | Value |
|---|---|
| Connections | 1 |
| Operation time | 60-90 minutes |
| Internal hernia | below 0.12% |
| Calcium per day | at least 1,500 mg |
| Serious complications nationally (2024) | 1.4% |
Mini bypass versus classic bypass versus sleeve
| Feature | Mini bypass | Classic bypass / Sleeve |
|---|---|---|
| Connections | 1 | 2 / none |
| Operation time | 60-90 min | 90-120 / 45-75 min |
| Internal hernia | below 0.12% | about 1-1.5% / n.a. |
| Reflux | some bile reflux | decreases / can increase |
| Reversible | convertible | technically possible / no |
Step by step
- Referral. Via your GP.
- Screening. The team checks which bypass fits you.
- Surgery. Keyhole operation of 60-90 minutes.
- Build-up of food. Liquid, puréed, then solid.
- Aftercare. At least five years, with blood tests.
Read next
- Gastric bypass (Roux-en-Y) — the classic version
- Sleeve or bypass: the difference — how teams choose
- Types of weight loss surgery — all options
- Cost and insurance — what you pay
Life after a mini gastric bypass
Eating after a mini bypass follows the same rules as after any bypass: six small meals a day, no drinking in the half hour before and after a meal, little sugar and fat, and chewing well. Dumping after sugar or fat is possible.
Because fat is absorbed less well, keep an eye on fatty, loose stools and report persistent complaints. Blood tests during aftercare check the fat-soluble vitamins in particular, so keep attending your check-ups, also after the first year.
Frequently asked questions about the mini gastric bypass
The mini bypass uses one connection between a long stomach tube and the small intestine; the classic bypass uses two, with a small stomach pouch. The mini bypass takes less time and causes fewer internal hernias, but bile reflux is slightly more common.
According to WeightWorks there are no differences in outcomes after twenty years. Weight loss is comparable, roughly 30 to 40 percent of total body weight.
Yes. It is one of the four standard operations and is covered by the basic package with a valid indication and referral. You pay your 385 euro deductible in 2026.
Bile flowing back up into the stomach tube, which can cause a bitter taste or burning. It is usually treatable with medication; if it persists, conversion to a classic bypass is possible.
Usually 60 to 90 minutes as keyhole surgery under general anaesthesia, somewhat shorter than a classic bypass.
A WLS multivitamin suited to the mini bypass and at least 1,500 mg of calcium with vitamin D a day. Fat-soluble vitamins A, D, E and K need extra attention because fat is absorbed less well.
Yes. It can be converted into a classic bypass, for example because of persistent bile reflux. This is a new operation with its own screening and risks.
It can happen, as with any bypass, after sugar or fat. Symptoms such as sweating, palpitations and dizziness usually pass within about 45 minutes.
Yes. WeightWorks reports a risk below 0.12 percent, compared with about 1 to 1.5 percent after a classic bypass, because there are fewer openings in the mesentery.
You decide together with the surgeon after screening. Reflux, anatomy, earlier operations and the centre's experience all play a role.
Call +31 6 38048347 (Mon–Fri 09:00–17:00) or email info@maagverkleining-info.nl. This page is also available in Dutch.
Sources
- WeightWorks: mini gastric bypass
- Stichting Bariatrie Groep Nederland: mini gastric bypass
- Vitalys (Rijnstate): FAQ
- DATO Annual Report 2024, DICA
Search terms leading here: mini gastric bypass Netherlands, OAGB Netherlands, one anastomosis gastric bypass, mini bypass vs gastric bypass.
Author: Gijs Bodenstaff. Last reviewed: September 2026.