SADI-S (Single-Anastomosis Duodeno-Ileal Bypass with Sleeve)

At a Glance

• What it is: A sleeve gastrectomy plus a single connection between the duodenum and the ileum, preserving the pylorus
• Who it is for: Recommended by the 2022 ASMBS/IFSO guidelines for adults with a BMI of 35 or higher, and considered at a BMI of 30–34.9 with metabolic disease (27.5 or higher for people of Asian descent) (Eisenberg et al., Surgery for Obesity and Related Diseases, 2022). Especially considered for higher BMI and severe type 2 diabetes
• Results: Greater weight loss than gastric bypass in a randomized trial (see Benefits and Landmark Evidence below)
• Main trade-off: Lifelong vitamin and mineral supplements and regular labs are essential
• Hospital stay and recovery: Usually one to two nights; desk work in about two weeks

SADI-S (single-anastomosis duodeno-ileal bypass with sleeve gastrectomy) was introduced in 2007 as a simplified evolution of the biliopancreatic diversion with duodenal switch (BPD/DS). It combines a sleeve gastrectomy with a single intestinal bypass (one anastomosis instead of two), which shortens operating time and reduces the risks of leak, anastomotic stricture, and internal hernia — while preserving the strong weight-loss and metabolic benefits of the duodenal switch (Obesity Surgery, 2024; Obesity Surgery, 2025).

Since 2020, both the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) and the American Society for Metabolic and Bariatric Surgery (ASMBS) have formally recognized SADI-S as a standard metabolic and bariatric procedure (Obesity Surgery, 2024; Obesity Surgery, 2026). Because it keeps the pylorus (the natural stomach-outlet valve) intact, SADI-S avoids the marginal ulcers, bile reflux, and dumping syndrome associated with some other bypass operations (Obesity Surgery, 2025; Obesity Surgery, 2021).

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To learn how SADI-S is offered at our Miami practice, and who is a good candidate for it, see SADI-S Surgery in Miami, FL.

SADI-S produces weight loss and metabolic improvement through three mechanisms:

• Restriction: The sleeve-shaped stomach holds much less food, so meals feel satisfying with smaller portions (Obesity Surgery, 2021).

• Malabsorption: A single connection between the duodenum (just past the preserved pylorus) and a loop of ileum reroutes food so that digestive juices mix with it only in a shortened common channel — typically 250–300 cm from the ileocecal valve — reducing calorie and fat absorption (Obesity Surgery, 2024; Obesity Surgery, 2018).

• Hormonal/metabolic change: Rerouting nutrients to the lower intestine, along with a longer biliopancreatic limb and favorable changes in gut hormones and bile acids, improves blood-sugar control — often rapidly and before major weight loss (Obesity Surgery, 2025).

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Greater weight loss than gastric bypass. In the randomized SADISLEEVE trial, SADI-S produced significantly higher excess weight loss than Roux-en-Y gastric bypass at 2 years (76.0% vs 68.1% EWL), with a similar safety profile (Lancet, 2025).

Higher diabetes remission. Pooled data from over 4,600 patients show significantly greater total weight loss, excess weight loss, and type 2 diabetes remission with SADI-S compared with gastric bypass (Obesity Surgery, 2025).

Technically simpler and safer than classic duodenal switch. The single anastomosis shortens operative time and reduces the risks of leak, stricture, and internal hernia (Obesity Surgery, 2025; Obesity Surgery, 2024).

Pylorus preservation. Keeping the pylorus lowers the risk of marginal ulcers, bile reflux, and dumping syndrome (Obesity Surgery, 2025).

Durable results. Long-term single-center data report roughly 38% total weight loss at 5 years and 34% at 10 years (Obesity Surgery, 2025; Obesity Surgery, 2022).

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SADI-S is generally best suited for:

• Adults with a high BMI (often ≥ 45–50 kg/m²) who need powerful, durable weight loss (Obesity Surgery, 2022).

• Patients with severe or difficult-to-control type 2 diabetes, including insulin-treated diabetes, regardless of BMI in some protocols (Obesity Surgery, 2022; Scientific Reports, 2024).

• Patients needing a more powerful operation after an inadequate response to a prior sleeve gastrectomy (second-stage or conversion procedure) (Obesity Surgery, 2026).

• People able and willing to commit to lifelong supplementation and regular follow-up blood tests (Obesity Surgery, 2024).

General candidacy follows standard bariatric thresholds: BMI ≥ 40, or ≥ 35 with an obesity-related condition, or 30–34.9 with inadequately controlled type 2 diabetes, adjusted for ethnicity (Clinical Practice Guidelines, ASMBS/AACE, 2020). SADI-S is generally not recommended for patients with inflammatory bowel disease, chronic diarrhea, or those unlikely to maintain close nutritional follow-up (Obesity Surgery, 2024).

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SADI-S is performed under general anesthesia using minimally invasive (laparoscopic or robotic) techniques through several small incisions. It has two components usually done in one operation: a sleeve gastrectomy with the pylorus preserved, followed by a single anastomosis connecting the first part of the duodenum to a loop of ileum, leaving a common channel of 250–300 cm. Because there is only one intestinal connection and no mesenteric division, operative time and certain technical risks are reduced (Obesity Surgery, 2024; Obesity Surgery, 2025). Most patients stay in the hospital 1–2 nights, and in selected low-risk patients it has been performed as an outpatient procedure (Obesity Surgery, 2025).

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SADI-S is considered safe and reproducible, with low early-complication rates, but it carries the nutritional risks inherent to malabsorptive surgery (Obesity Surgery, 2024).

• Early complications are uncommon: pooled reoperation, bleeding, and anastomotic leak rates of roughly 3.1%, 1.1%, and 0.9%, respectively (Obesity Surgery, 2024). In the SADISLEEVE trial, serious surgical adverse events were comparable to gastric bypass, though severe diarrhea was more frequent after SADI-S (Lancet, 2025).

• Nutritional deficiencies are the most important long-term risk, especially fat-soluble vitamins (A, D, E, K), iron, and protein. Reported ranges are wide — for example, vitamin D deficiency 24–62%, vitamin A deficiency up to ~45%, iron/ferritin deficiency 10–67%, and protein/albumin deficiency up to ~17–41% depending on common-channel length and supplementation (Obesity Surgery, 2023; Scientific Reports, 2024).

• Bowel-related effects, including more frequent, loose, or foul-smelling stools and excess gas from fat malabsorption (Obesity Surgery, 2024).

• Protein malnutrition and, rarely, the need for surgical revision (e.g., lengthening the common channel) for severe malnutrition or excessive weight loss (ASMBS, 2026).

A shorter common channel (200 cm) increases nutritional risk; the now-standard 250–300 cm channel was adopted to reduce deficiencies (Obesity Surgery, 2024; Scientific Reports, 2024).

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Most patients return to normal activity within a few weeks. Diet advances in stages — clear liquids, full liquids, pureed foods, then solids — over several weeks under the guidance of the surgical and nutrition team. Lifelong daily vitamin and mineral supplements begin right away, along with a high-protein diet (typically at least 60–80 g per day) (Obesity Surgery, 2023; Scientific Reports, 2024).

Weight loss reaches its peak within the first 1–2 years and is well maintained long term. Long-term single-center data report excess weight loss and total weight loss of roughly 87% and 38% at 5 years and 80% and 34% at 10 years (Obesity Surgery, 2025; Obesity Surgery, 2022). Lifelong annual nutritional blood tests are essential to safe, durable success (Obesity Surgery, 2024).

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Landmark Evidence

• After prior bariatric surgery: in patients converted after a failed band, a single-anastomosis duodenal switch produced greater weight loss than sleeve conversion, and the prior operation did not blunt its effect (Pearlstein et al., Obesity Surgery, 2019).
• Why limb length matters: in malabsorptive operations, shorter absorptive lengths are linked to severe protein-energy malnutrition (systematic review and meta-analysis, Annals of Surgery, 2021), which is why SADI-S keeps a long common channel.
• Survival: Across 17 studies and more than 174,000 people, metabolic and bariatric surgery was associated with a 49% lower risk of death and a median of 6.1 additional years of life compared with non-surgical care. The benefit was greatest in people with type 2 diabetes (Syn et al., The Lancet, 2021).

How It Compares

• Versus duodenal switch: one connection instead of two and a longer common channel, so it is simpler and gentler on nutrition, with slightly less effect.
• Versus gastric bypass: more powerful for weight and diabetes and preserves the pylorus, but carries greater nutritional demands and a sleeve that may cause reflux.
• Versus MagDI: MagDI diverts only part of each meal through a magnet-formed connection and is still emerging.

More in Bariatric Surgery Procedures

Related procedures: Duodenal Switch, Magnetic Duodeno-Ileal Bypass with Sleeve, Adjustable Gastric Band Surgery, Medical Weight Loss Program, Robotic Surgery, Sleeve Gastrectomy. For an overview of all options, see Bariatric Surgery.

Conditions treated: Obesity, Type 2 Diabetes, Sleep Apnea, Metabolic Dysfunction–Associated Steatohepatitis, Metabolic Syndrome, High Blood Pressure.

Dr. Nestor de la Cruz-Muñoz is a bariatric and metabolic surgeon whose outcomes are tracked through the national MBSAQIP quality program. He applies his high-volume experience, advanced minimally invasive techniques, and long-term metabolic support model with the goal of safe, effective, and compassionate care.

SADI-S is a precise malabsorptive operation, and results depend on surgical judgment. Dr. de la Cruz-Muñoz has over 25 years of bariatric surgery experience and more than 9,000 bariatric operations, a volume few surgeons reach.

Whether you live nearby or are coming from out of state, practical information on scheduling, surgery and aftercare is on our SADI-S surgery in Miami page.

Authored by Nestor de la Cruz-Muñoz, MD, FACS, DABOM. Last updated November 2026.

• 1 year: ~40% TBWL (excess weight loss consistently above 60%) (Obesity Surgery, 2021).

• 2 years: superior to gastric bypass — 76.0% vs 68.1% excess weight loss in a randomized trial (Lancet, 2025).

• 5 years: ~38% TBWL (Obesity Surgery, 2025; Obesity Surgery, 2022).

• 10 years: ~34% TBWL (Obesity Surgery, 2025).

Individual results vary with starting weight, common-channel length, diet, and adherence to follow-up.

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Type 2 diabetes: Remission in roughly 70–73% of patients, significantly higher than gastric bypass, and durable even in advanced, insulin-treated diabetes (Obesity Surgery, 2025; Obesity Surgery, 2021).

Dyslipidemia: Improvement or resolution in roughly 77% of patients (Obesity Surgery, 2021).

Hypertension: Resolution in roughly 59% of patients; similar to gastric bypass (Obesity Surgery, 2021; Obesity Surgery, 2024).

Obstructive sleep apnea: High rates of improvement or resolution (Obesity Surgery, 2024).

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SADI-S has a relatively low weight-regain rate because of its malabsorptive component, but maintaining results still depends on a high-protein diet, consistent daily supplementation, regular physical activity, and keeping all follow-up appointments so nutrition and weight trends are caught early (Obesity Surgery, 2024). When significant regain occurs after other procedures, conversion to SADI-S is itself an effective revisional option, adding meaningful additional weight loss (Obesity Surgery, 2026).

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Because SADI-S preserves the pylorus, it avoids the bile reflux seen with some single-anastomosis bypasses. Because it is built on a sleeve, however, it does not correct acid reflux and can contribute to it in some patients. Patients with significant or medication-resistant GERD need individualized evaluation and are usually better served by gastric bypass (Obesity Surgery, 2025).

SADI-S is commonly used as a second-stage or conversion procedure after an inadequate response to sleeve gastrectomy or other operations, producing durable additional weight loss (Obesity Surgery, 2026; Obesity Surgery, 2026). If a patient develops severe malnutrition, hypoalbuminemia, or excessive weight loss after SADI-S, the common channel can be lengthened or the anatomy revised (ASMBS, 2026). Overall revision rates are low, but lifelong monitoring helps catch problems early.

Rapid, large weight loss carries a risk of losing muscle along with fat, and the malabsorptive nature of SADI-S makes adequate protein intake especially important. A protein target of at least 60–80 g per day, combined with resistance exercise, helps preserve lean muscle mass. Protein and albumin levels are monitored at every follow-up visit, since hypoalbuminemia is a recognized risk (Obesity Surgery, 2023; Scientific Reports, 2024).

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Most insurers require documentation of a qualifying BMI (typically ≥ 40, or ≥ 35 with obesity-related conditions), a medically supervised weight-management program, and nutritional and psychological evaluation. Because SADI-S is a newer procedure, some plans may require additional documentation or may not yet cover it; our team verifies specific coverage before scheduling (Clinical Practice Guidelines, ASMBS/AACE, 2020).

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Complete nutritional, psychological, and medical evaluations (Obesity Surgery, 2022).

Baseline laboratory testing, including a full nutritional panel, and often an upper endoscopy (Obesity Surgery, 2022).

Begin dietary changes and any recommended pre-operative weight loss.

Stop smoking and arrange for long-term supplement supplies and follow-up support.

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Lifelong supplementation is mandatory after SADI-S. Typical regimens include daily multivitamins, high-dose fat-soluble vitamins (A, D, E, K), calcium citrate, iron, zinc, and vitamin B12, with doses adjusted based on regular blood tests (Obesity Surgery, 2023). A high-protein diet of at least 60–80 g per day is essential. Even with careful supplementation, deficiencies can occur and require ongoing monitoring and dose adjustments (Scientific Reports, 2024).

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Walking begins the day of surgery to reduce clot risk. Light activity resumes within the first week or two, with a gradual return to full exercise over 4–6 weeks. Once cleared, a combination of regular aerobic activity and resistance training supports muscle preservation and long-term weight maintenance.

SADI-S patients from abroad should plan to stay in Miami for approximately one week. Before you travel, our team confirms that bariatric vitamins and lab testing are available near you. Follow-up visits are virtual, and lab results from home are reviewed for life.