Gastric bypass to OAGB conversion is a revisional bariatric procedure for patients who experience inadequate weight loss, weight regain, metabolic relapse, or complications after Roux‑en‑Y gastric bypass (RYGB). The procedure reverses the bypass anatomy, restores normal stomach continuity, and creates a long gastric pouch connected to the small intestine in a single‑anastomosis configuration. OAGB provides stronger metabolic improvement and more durable long‑term weight loss than RYGB alone.

The gastric bypass is reversed by reconnecting the gastric pouch to the remnant stomach. A long, narrow gastric pouch is created. The small intestine is measured and connected to the pouch in a single‑anastomosis loop. This enhances metabolic signaling, reduces calorie absorption, and simplifies the anatomy compared to RYGB.

Benefits include improved metabolic outcomes, enhanced weight loss durability, reduced hunger, improved satiety, and resolution of certain bypass‑related complications such as dumping syndrome or marginal ulcers. OAGB offers a simpler, more powerful metabolic configuration.

Candidates include patients with inadequate weight loss after bypass, weight regain, metabolic disease recurrence, severe dumping syndrome, marginal ulcers, or complications related to the gastric pouch or gastrojejunostomy.

The procedure is performed laparoscopically. The bypass is reversed, a long gastric pouch is created, and the small intestine is connected to the pouch in a single‑anastomosis configuration. Most patients stay one night in the hospital.

Risks include bleeding, leak, stricture, bile reflux, marginal ulcer, nutritional deficiencies, and weight regain if long‑term habits are not maintained. Revisional surgery carries higher complexity due to scar tissue and altered anatomy.

Days 1–3: hydration, ambulation, pain control. Week 1: liquids. Week 2: soft foods. Weeks 3–4: gradual return to normal routines. By 30 days: improved energy, reduced hunger, and early metabolic improvements.

Patients typically experience improved metabolic outcomes and steady fat loss over 12–18 months. OAGB offers more durable long‑term results than RYGB alone.

Dr. Nestor de la Cruz‑Muñoz is a national leader in complex revisional bariatric surgery, including bypass reversal and advanced metabolic procedures such as OAGB. His expertise ensures safe reconstruction and optimal long‑term outcomes.

Most patients lose 18–26% of total body weight (TBWL) over 12–18 months after conversion. Results depend on adherence to nutrition, activity, and follow‑up.

OAGB conversion offers strong improvement in type 2 diabetes, insulin resistance, hypertension, dyslipidemia, sleep apnea, and fatty liver disease.

Long‑term success requires protein‑forward nutrition, resistance training, avoiding slider foods, maintaining muscle mass, and consistent metabolic follow‑up. Body composition monitoring is essential.

OAGB may improve reflux in some patients but may worsen bile reflux in others. Patients with severe GERD may benefit more from RYGB revision rather than reversal. Hiatal hernia repair is performed when needed.

Future revision options include limb length adjustments, pouch resizing, conversion to SADI‑S or DS for metabolic failure, or conversion back to RYGB for bile reflux.

Preserving lean mass is essential for long‑term success. Patients are guided to prioritize protein intake, resistance training, hydration, and body composition monitoring.

Insurance coverage varies. Documentation of inadequate weight loss, metabolic disease, or bypass‑related complications may be required.

Pre‑op requirements may include bloodwork, imaging, endoscopy, nutrition consultation, psychological evaluation, and medication adjustments.

Nutrition progresses from clear liquids to full liquids, purees, soft foods, and then regular textures. Protein goals and vitamin supplementation are essential.

Early walking begins immediately after surgery. Light activity continues through week 2. Resistance training typically begins at week 4–6.

Miami is a major hub for patients from Latin America and the Caribbean. Our team supports travel coordination, virtual follow‑up, and streamlined pre‑op evaluation.