- Stomach tube plus a long bypass of the small intestine.
- Mostly a second step, about two years after a sleeve.
- Most additional weight loss of all operations.
- Fat is absorbed poorly: strict vitamin follow-up.
- A standard operation, covered with a valid indication.
What is a SADI operation?
In a SADI the stomach is first made into a sleeve, if that has not already happened. Just below the stomach, the duodenum is then connected to a loop of small intestine far down, so food bypasses a long stretch of intestine. Because food and digestive juices meet late, much less fat and fewer calories are absorbed.
At a very high starting weight, Dutch centres sometimes plan a two-step approach deliberately: first a sleeve, then about two years later a SADI to lose more weight. Vitalys also mentions a favourable effect of the SADI on type 2 diabetes.
What do SADI symptoms after eating feel like?
Vitalys describes that after eating, blood moves to the intestines and blood pressure in the brain drops. You may become sleepy or dizzy, sometimes with palpitations and sweating. Drinking a glass of water and lying down quietly helps. Loose, fatty stools can occur after fatty meals, which is one reason to keep fat intake low.
Who is the SADI suitable for?
Mainly people who have had a sleeve and lost too little weight, or regained weight, and people with a very high BMI for whom a two-step approach was planned. Severe reflux after a sleeve is usually a reason to choose a bypass rather than a SADI.
Because of the strong malabsorption, the SADI demands discipline: special supplements, regular blood tests and a protein-rich diet for life. Centres only offer it when they are confident you can keep up that aftercare.
Advantages and points of attention: sadi and duodenal switch
Advantages
| Advantage | Explanation |
|---|---|
| Most extra weight loss | strongest effect of all operations |
| Type 2 diabetes | favourable effect (Vitalys) |
| One connection | simpler than the classic duodenal switch |
| Logical second step | after an earlier sleeve |
Points of attention
| Point of attention | Explanation |
|---|---|
| Malabsorption | fat and fat-soluble vitamins |
| Strict aftercare | special supplements and blood tests |
| Bowel habits | loose stools after fatty food |
| Second operation | higher risk than a first procedure |
Cost and insurance (2026)
The SADI is a standard operation under the Dutch guideline and covered with a valid indication.
| Item | Amount or arrangement |
|---|---|
| Covered pathway | €385 deductible (2026) |
| Special SADI supplements | not covered |
| Revision from a sleeve with medical reason | basic package |
SADI and duodenal switch: key figures
| Feature | Value |
|---|---|
| Typical timing | about 2 years after a sleeve |
| Connections | 1 |
| Supplements | special SADI formula, for life |
| Protein | high-protein diet needed |
| Serious complications nationally (2024) | 1.4% |
SADI compared with a bypass after a sleeve
| Feature | SADI | Bypass after sleeve |
|---|---|---|
| Extra weight loss | most | moderate |
| Effect on reflux | limited | usually improves |
| Malabsorption | strong | moderate |
| Aftercare | strictest | standard bypass follow-up |
Step by step
- Evaluation. Too little loss or regain after a sleeve.
- New screening. Medical, dietary and psychological.
- Surgery. Keyhole conversion to SADI.
- Supplements. Start special SADI vitamins.
- Aftercare. Close follow-up with blood tests.
Read next
- Gastric sleeve as the first step — stomach only
- Revision surgery after a sleeve — second operations
- Types of weight loss surgery — all options
- Cost and insurance — coverage
Eating after a SADI
A high-protein diet with little fat is the basis after a SADI. Fatty meals are poorly absorbed and can cause loose stools and wind, while protein is needed to keep muscle mass during fast weight loss. Small, regular meals help prevent the drowsiness and dizziness some people feel after eating.
Supplements are designed specifically for the SADI and are not interchangeable with bypass or sleeve vitamins. Keep taking them even when you feel well: deficiencies of fat-soluble vitamins develop slowly and are only visible in blood tests. That is why centres only offer the SADI when they are confident you can keep up strict aftercare.
Plan your meals around your day: many people find that small portions spread out over the day cause the fewest symptoms.
Questions to ask before a SADI
Ask the centre how many SADI operations it performs, which supplements it prescribes, how often blood tests are taken in the first years and what happens if deficiencies occur. The answers tell you how well the aftercare is organised.
Frequently asked questions about the SADI
Single anastomosis duodeno-ileal bypass, sometimes written SADI-S when combined with a sleeve. It is a simplified version of the duodenal switch with one connection.
Mostly as a second step after a gastric sleeve, for example about two years later when weight loss was insufficient or at a very high starting weight.
It gives the most additional weight loss of all standard operations. The exact amount depends on your starting weight, the earlier sleeve and how well you follow the aftercare.
Yes, it is a standard operation under the Dutch guideline and covered with a valid indication and referral. Special supplements are not covered.
Because much less fat is absorbed, deficiencies of vitamins A, D, E and K and other nutrients can develop quickly. Regular blood tests and special supplements prevent this.
Sleepiness, dizziness, sometimes palpitations and sweating, as blood moves to the intestines. Drinking water and lying down helps. Fatty meals can cause loose stools.
It depends. The SADI gives more weight loss; a bypass is usually better when reflux is the main problem after a sleeve. The team decides with you.
Vitalys mentions a favourable effect on type 2 diabetes, similar to other operations that reroute the intestine.
It is possible, but in the Netherlands it is mainly used as a second step. The team considers your BMI and overall health.
Similar to other keyhole operations, on average three to six weeks, but the dietary adjustment and follow-up continue for life.
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): SADI and FAQ
- Richtlijn Chirurgische behandeling van obesitas, NVvH
- DATO Annual Report 2024, DICA
Search terms leading here: SADI surgery Netherlands, SADI-S Netherlands, duodenal switch Netherlands, second step after gastric sleeve.
Author: Gijs Bodenstaff. Last reviewed: September 2026.