Sleeve Gastrectomy to Duodenal Switch (DS) Conversion

The sleeve gastrectomy began as the first half of the duodenal switch. It was first used as a first-stage operation for very high-risk patients, with the intestinal portion of the duodenal switch added later once weight and surgical risk had come down. The American Society for Metabolic and Bariatric Surgery (ASMBS) still endorses the sleeve both as a primary operation and as the first stage of a planned, staged approach (Pontecorvo et al., Obesity Surgery, 2025).

Over time the sleeve became the most common weight-loss operation in the world, and many patients eventually need more. Beyond 7 years, long-term weight regain after sleeve exceeds 27.8% in pooled data (Pontecorvo et al., Obesity Surgery, 2025). In U.S. accredited-center data, more than 91% of sleeve-to-DS conversions are done for weight loss failure or regain (Vanetta et al., Obesity Surgery, 2022). See Sleeve Gastrectomy and Revisional Bariatric Surgery for background.

Sleeve-to-DS conversion keeps your existing sleeve. The surgeon divides the duodenum just past the stomach outlet (pylorus) and connects it to the lower small intestine (ileum). Bile and digestive juices are rerouted to join food only in the final 75–150 cm of intestine, called the common channel (Franken et al., Obesity Surgery, 2022; El Ghazal et al., Surgical Endoscopy, 2025).

Among sleeve revisions, DS consistently produces some of the largest weight loss:

• In a matched study, second-stage DS reached 42.3% total weight loss at 3 years. That was statistically similar to performing a full DS in one operation (Biertho et al., Surgery for Obesity and Related Diseases, 2018).

• In a long-term comparison with median follow-up of about 6 years, DS produced the highest added weight loss of any sleeve revision. Every patient with diabetes achieved remission (Almuallem et al., Obesity Surgery, 2026).

• In a 2025 comparison of conversions for weight regain, DS produced significantly more weight loss than RYGB at 6, 12, and 24 months (Pontecorvo et al., Obesity Surgery, 2025).

DS is not the right revision for everyone. In an international expert consensus of bariatric surgeons, 90% agreed DS should be avoided in patients with weight regain plus reflux or an enlarged fundus. Roux-en-Y gastric bypass is preferred in that situation (Merz et al., Surgery for Obesity and Related Diseases, 2019). See Sleeve Gastrectomy to Roux-en-Y Gastric Bypass Conversion.

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DS conversion adds two powerful mechanisms to the restriction your sleeve already provides:

• Malabsorption. Food travels through a long alimentary limb (typically about 250 cm) and only meets bile and pancreatic enzymes in the common channel (Lind et al., Obesity Surgery, 2022). Fat and calorie absorption fall sharply. This is the main reason DS outperforms other revisions for weight loss, and it is also the source of its nutritional risk.

• Hormonal and metabolic change. Food bypasses the duodenum and arrives at the lower intestine early. This changes gut hormone signaling and bile acid metabolism, which drives the highest diabetes remission rates of any bariatric operation. In randomized trials in patients with severe obesity, DS produced significantly greater BMI reduction than gastric bypass (Colquitt et al., Cochrane Database of Systematic Reviews, 2014).

• The pylorus is preserved. Your natural stomach outlet stays in place. That means no dumping syndrome in most patients and a much lower marginal ulcer risk than gastric bypass. But the preserved pylorus keeps pressure inside the sleeve high, which is why reflux matters so much in choosing this operation (Mingrone et al., The Lancet Diabetes & Endocrinology, 2018).

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• The most weight loss of any sleeve revision:
  • 42.3% total weight loss at 3 years, measured from pre-sleeve weight (Biertho et al., Surgery for Obesity and Related Diseases, 2018)
  • Pooled data cited in a 2026 study: 28% added total weight loss at 3 years after DS, compared with 19% after SADI-S and 13% after RYGB (Almuallem et al., Obesity Surgery, 2026)
  • About 36% total weight loss at 5 years in a mid- to long-term series (Almuallem et al., Obesity Surgery, 2026)
• Diabetes and blood pressure remission comparable to a one-stage DS:
  • Type 2 diabetes remission rose from 59% after sleeve to 94% after DS conversion
  • Hypertension remission rose from 42% to 77% (Biertho et al., Surgery for Obesity and Related Diseases, 2018)
• Thirty-day safety similar to conversion to bypass. In U.S. registry data on more than 6,000 sleeve conversions, DS had:
  • No deaths
  • Overall complications of 5.1% vs 6.5% for RYGB conversion
  • Fewer readmissions (5.4% vs 7.3%)
  • Less dehydration (2.2% vs 4.2%) (Spivak et al., Surgery for Obesity and Related Diseases, 2023)

• Fewer minor complications than bypass-type conversions in a larger 2026 analysis of 18,179 sleeve conversions (Salas-Parra et al., Surgical Endoscopy, 2026)

• Keeps your sleeve and pylorus, so no stomach pouch is created and no new stomach-to-intestine connection is made

• Durable weight control for patients who regained after a restrictive operation

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• Sleeve patients with significant weight regain or inadequate weight loss, especially those with a higher BMI at revision (Merz et al., Surgery for Obesity and Related Diseases, 2019)

• Patients whose sleeve was performed for super obesity (BMI 50 or higher). In expert consensus, 96.7% agreed DS is most appropriate as a second stage after sleeve for super obesity (Merz et al., Surgery for Obesity and Related Diseases, 2019).

• Reliable patients with insufficient weight loss after sleeve. 88.5% of experts agreed with this indication (Merz et al., Surgery for Obesity and Related Diseases, 2019).

• Patients with persistent or recurrent type 2 diabetes who want the strongest metabolic effect available (Biertho et al., Surgery for Obesity and Related Diseases, 2018)

• Patients with no significant reflux, confirmed by upper endoscopy and, when indicated, pH testing and esophageal manometry

• Patients committed to lifelong high-dose vitamins, protein targets, and lab monitoring. Good adherence is the single best protection against malnutrition (Vosburg et al., Surgery for Obesity and Related Diseases, 2026).

Who is usually better served by a different operation:

• Reflux, erosive esophagitis, Barrett's esophagus, a hiatal hernia, or a dilated upper sleeve. Choose Sleeve Gastrectomy to Roux-en-Y Gastric Bypass Conversion (Merz et al., Surgery for Obesity and Related Diseases, 2019). See also Hiatal Hernia Repair After Sleeve Gastrectomy and Gastric Bypass (Roux-en-Y) for GERD.

• Patients who want strong weight loss with one intestinal connection and somewhat lower nutritional risk. See Sleeve to SADI-S Conversion and Sleeve to MagDI Conversion.

• Heavy alcohol use, existing liver disease, or a history of poor follow-up. These raise the risk of severe malnutrition after DS (Vosburg et al., Surgery for Obesity and Related Diseases, 2026).

• A dilated sleeve or retained fundus without reflux, at a lower BMI. See Re-Sleeve Gastrectomy.

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Sleeve-to-DS conversion is performed laparoscopically or robotically under general anesthesia:

1. Assessment of the sleeve and hiatus. Adhesions from the first operation are released, and the sleeve and diaphragm opening are inspected.
2. Measuring the intestine. The small bowel is measured backward from the ileocecal valve. The point for the new connection is marked about 250–300 cm up (Franken et al., Obesity Surgery, 2022; Lind et al., Obesity Surgery, 2022).
3. Dividing the duodenum. The duodenum is divided with a stapler 2–3 cm beyond the pylorus (Franken et al., Obesity Surgery, 2022; Lind et al., Obesity Surgery, 2022).
4. Duodeno-ileostomy. The marked ileum is brought up and connected to the duodenum, often with a hand-sewn, double-layer anastomosis (Lind et al., Obesity Surgery, 2022).
5. Ileo-ileostomy. The biliopancreatic limb is joined to the alimentary limb to create the common channel. Reported lengths range from 60–100 cm in older series to 125–150 cm in modern practice (Franken et al., Obesity Surgery, 2022; Lind et al., Obesity Surgery, 2022; El Ghazal et al., Surgical Endoscopy, 2025).
6. Closing mesenteric defects. These openings are closed to reduce the risk of internal hernia (Dapri et al., Surgery for Obesity and Related Diseases, 2018).
7. Leak testing. The connections are checked for leaks.

Operating time is longer than for RYGB conversion. In one series it was about 3 hours for DS vs about 2 hours for RYGB (Carmeli et al., Surgery for Obesity and Related Diseases, 2014).

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Revision always carries more risk than a first operation. In national data on almost 95,000 conversions, revision to DS/SADI anatomy added about 17.5 serious adverse events per 1,000 patients compared with a primary operation (Dallal et al., Surgery for Obesity and Related Diseases, 2026).

Early (first 30 days):

• Anastomotic leak: 1.2%, compared with 0.5% after RYGB conversion (Spivak et al., Surgery for Obesity and Related Diseases, 2023)

• Major 90-day complications: 5%, with no deaths in a matched series (Biertho et al., Surgery for Obesity and Related Diseases, 2018)

• Bleeding, infection, blood clots, and readmission

Long-term:

• Protein-calorie malnutrition. Revision for malnutrition after DS is reported in 0.5–10.6% of patients, with most series between 1% and 5%. About 75% of these revisions occur within the first 18 months (Vosburg et al., Surgery for Obesity and Related Diseases, 2026). In one sleeve-to-DS series, 14% had nutritional complications and 2 of 21 patients needed common channel lengthening (Franken et al., Obesity Surgery, 2022).

• Vitamin and mineral deficiencies. Fat-soluble vitamins (A, D, E, K), iron, B12, and zinc are most commonly affected (Nett et al., Obesity Surgery, 2016).

• Diarrhea and foul-smelling stools, especially after high-fat meals

• Internal hernia (Almuallem et al., Obesity Surgery, 2026)

• Kidney stones, gallstones, and, rarely, liver impairment (Lind et al., Obesity Surgery, 2024)

Reflux is covered separately below.

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• Hospital stay: typically 2–4 days. One series reported an average of 4.3 days (Carmeli et al., Surgery for Obesity and Related Diseases, 2014), and enhanced recovery protocols shorten this for many patients.

• Walking: starts the day of surgery.

• Diet: progresses from clear liquids to full liquids, purées, soft foods, and regular foods over about 6–8 weeks.

• Hydration: at least 64 oz a day. Dehydration is a leading cause of readmission after any conversion.

• Return to work: most patients go back to desk work in 2–4 weeks.

• Labs: the first nutritional labs are checked within the first 3 months, the period when malnutrition most often appears.

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• Weight loss:
  • About 80% excess weight loss at 2 and 3 years after second-stage DS (Biertho et al., Surgery for Obesity and Related Diseases, 2018)
  • BMI reduction of about 14 points sustained beyond 4 years in another series (Franken et al., Obesity Surgery, 2022)

• Diabetes: DS produces the highest diabetes remission of any sleeve revision (Almuallem et al., Obesity Surgery, 2026).

• Follow-up: lifelong. Labs are checked every 3–6 months in the first year, then at least yearly.

• What remains uncertain: most data come from retrospective series, and longer-term outcomes after staged DS are still needed (Biertho et al., Surgery for Obesity and Related Diseases, 2018).

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More in Sleeve Gastrectomy Revisions

Related procedures: Sleeve to OAGB Conversion, Sleeve Gastrectomy to Magnetic Duodeno-Ileostomy Conversion, Re-Sleeve Gastrectomy, Hiatal Hernia Repair After Sleeve Gastrectomy, Gastric Sleeve Stricture Management, Sleeve Gastrectomy to Roux-en-Y Gastric Bypass Conversion. Related primary operations: Sleeve Gastrectomy, Duodenal Switch. For an overview of all options, see Revisional Bariatric Surgery.

Conditions treated: Weight Regain, Inadequate Weight Loss, Acid Reflux, Stomach Narrowing (Stricture) After Bariatric Surgery, Hiatal Hernia & Paraesophageal Hernia, Barrett’s Esophagus.

Few U.S. surgeons offer sleeve-to-DS conversion. In national data, it accounted for only 6.3% of sleeve conversions, while 85% went to Roux-en-Y bypass (Salas-Parra et al., Surgical Endoscopy, 2026). Expert surgeons agree that its use is limited by its technical difficulty (Merz et al., Surgery for Obesity and Related Diseases, 2019). Its success also depends on two things: choosing the right patient and setting the right common channel length.

Dr. Nestor de la Cruz-Muñoz, MD, FACS, DABOM, is a board-certified surgeon and a diplomate of the American Board of Obesity Medicine, so he treats obesity both medically and surgically. He served for 10 years as a bariatric surgery fellowship program director, training surgeons in duodenal switch, single-anastomosis, and revisional operations. His practice is also a referral center for reflux and hiatal hernia surgery. That matters here because ruling out reflux is the single most important step before choosing DS over bypass.

His program offers every sleeve revision option in one place:

• Sleeve Gastrectomy to Duodenal Switch (DS) Conversion

• Sleeve to SADI-S Conversion

• Sleeve to MagDI Conversion

• Sleeve to OAGB Conversion

• Sleeve Gastrectomy to Roux-en-Y Gastric Bypass Conversion

• Re-Sleeve Gastrectomy

• Anti-obesity medication

Every evaluation includes:

• Upper endoscopy

• Reflux and esophageal function testing when indicated

• Imaging of the sleeve

• A full nutritional baseline

If malnutrition develops, common channel lengthening or revision is managed by the same team.

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Dr. de la Cruz-Muñoz has been performing bariatric surgery for over 25 years and has completed more than 9,000 bariatric operations — a volume few surgeons reach.

Measured from your original pre-sleeve weight (Biertho et al., Surgery for Obesity and Related Diseases, 2018):

• 1 year after conversion: about 39%

• 2 years: about 41%

• 3 years: about 42%

Additional weight loss measured from your weight at the time of revision:

• About 20% at a median of about 6 years (Almuallem et al., Obesity Surgery, 2026)

• About 28% at 3 years in pooled data (Almuallem et al., Obesity Surgery, 2026)

Individual results vary with BMI at revision, common channel length, nutrition, activity, and follow-up.

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• Type 2 diabetes:
  • Remission rose from 59% to 94% after conversion (Biertho et al., Surgery for Obesity and Related Diseases, 2018)
  • 100% remission among patients with diabetes in a long-term series (Almuallem et al., Obesity Surgery, 2026)

• Hypertension: remission rose from 42% to 77% (Biertho et al., Surgery for Obesity and Related Diseases, 2018)

• Cholesterol and triglycerides: DS lowers these strongly because of reduced fat absorption.

• Sleep apnea and fatty liver: improve with weight loss. Liver function is monitored because liver impairment, although uncommon, can occur after DS (Lind et al., Obesity Surgery, 2024).

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• Structured follow-up at 1, 3, 6, 9, and 12 months, then at least once a year for life

• Protein-first eating, with targets set by your dietitian (often higher than after other operations)

• Resistance training at least 2 days a week

• Body composition tracking, not just scale weight

• Early use of anti-obesity medication if a plateau or regain occurs

• Limiting alcohol, which raises both regain and liver risk after DS (Vosburg et al., Surgery for Obesity and Related Diseases, 2026)

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Reflux is the most important deciding factor between DS and gastric bypass.

• Why DS doesn't fix reflux: DS keeps both the sleeve and the pylorus, so the high-pressure sleeve that causes reflux stays in place. In long-term follow-up of primary DS, reflux rose from 8.8% to 38.1% over 10 years (Mingrone et al., The Lancet Diabetes & Endocrinology, 2018).
• Pooled data from 14 studies:
  • 18% developed new reflux after DS
  • 49% with pre-existing reflux improved
  • 14% got worse
  • Reflux was twice as likely to improve after RYGB as after DS
  • 4–12% of patients eventually needed reflux surgery (Brand et al., Surgical Endoscopy, 2025)

• Expert recommendation: with weight regain plus reflux, Roux-en-Y gastric bypass is preferred and DS should be avoided (Merz et al., Surgery for Obesity and Related Diseases, 2019).

Patients with reflux are directed to Sleeve Gastrectomy to Roux-en-Y Gastric Bypass Conversion. See also GERD / Acid Reflux, Barrett's Esophagus, and Hiatal Hernia Repair After Sleeve Gastrectomy.

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• Common channel lengthening. This is the standard treatment for malnutrition that doesn't respond to intensive nutritional support. In one series, moving the connection 100 cm upstream raised albumin from 3.6 to 4.0 g/dL, with modest weight regain and 15% perioperative complications (Vosburg et al., Surgery for Obesity and Related Diseases, 2026).

• Reversal. This is reserved for severe, refractory malnutrition or liver impairment (Lind et al., Obesity Surgery, 2024).

• Conversion to Roux-en-Y anatomy. This is used for severe reflux after DS (Brand et al., Surgical Endoscopy, 2025). See Revisional Bariatric Surgery.

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DS causes the most rapid weight loss of any revision. Protecting muscle is essential. The program includes:

• Baseline and periodic body composition testing (InBody or DEXA)

• Higher daily protein targets, often with protein supplements

• Progressive resistance training starting around 4–6 weeks after surgery

• Monitoring of vitamin D, calcium, and PTH to protect bone, because fat-soluble vitamin deficiency is common after DS (Nett et al., Obesity Surgery, 2016)

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Most insurers cover revisional surgery when medical necessity is documented, including inadequate weight loss, metabolic disease, or sleeve complications. Most plans that cover revisional surgery require:

• Documented weight regain or inadequate weight loss after sleeve

• A current qualifying BMI, typically 35 or higher, or 30 or higher with metabolic disease (Eisenberg et al., Obesity Surgery, 2023)

• Records of your original operation

• Nutrition and psychological evaluations

• Sometimes a supervised weight program

Some policies limit coverage to one bariatric operation per lifetime. Coverage must be verified for each plan.

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• Upper endoscopy to rule out esophagitis, Barrett's esophagus, and hiatal hernia

• pH testing and esophageal manometry when reflux symptoms are present

• An upper GI study or CT to assess sleeve shape
• Baseline labs:
  • Albumin and prealbumin
  • Vitamins A, D, E, and K
  • Iron studies, B12, and folate
  • Zinc, copper, and thiamine
  • PTH and liver function

• Correcting existing deficiencies before surgery

• Stopping smoking and limiting alcohol

• A pre-operative liquid diet

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• Lifelong supplements:
  • High-potency bariatric multivitamin
  • Fat-soluble vitamins (A, D, E, K), often in water-miscible forms
  • Calcium citrate
  • Iron, B12, and zinc as indicated
  Supplement doses vary between patients, and prescribed doses aren't always enough, so lab-guided adjustment is essential (Nett et al., Obesity Surgery, 2016).

• High protein intake every day

• Lower-fat meals to limit diarrhea
• Signs to report right away:
  • Swelling, hair loss, or extreme fatigue, which can signal protein malnutrition
  • Night blindness, which can signal vitamin A deficiency

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• Weeks 0–2: walk several times a day and build up to 30 minutes.

• Weeks 2–6: do light cardio. Avoid lifting over 15–20 lbs.

• After 6 weeks: add progressive resistance training at least 2 days a week.

• Long-term: aim for 150+ minutes a week of activity plus strength work.

• Hydration: stay hydrated before, during, and after exercise

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For sleeve-to-duodenal-switch conversion, international patients should plan a stay of 7–10 days and confirm access to fat-soluble vitamins and blood testing at home. Our team provides a written supplement plan in English or Spanish.