Mini Gastric Bypass in Mérida

Dr. Montserrat Monroy · Board-Certified Bariatric Surgeon (CMCG)
Last medical review: July 2026

What Is Mini Gastric Bypass?

Mini gastric bypass, also known as one-anastomosis gastric bypass (OAGB), is a bariatric and metabolic surgery that combines stomach size restriction with an intestinal malabsorptive component. Unlike traditional gastric bypass, which creates two intestinal connections, mini bypass creates a single anastomosis, simplifying the surgical technique.

During the procedure, a long, narrow gastric reservoir is created from the stomach and connected directly to a loop of the small intestine, leaving a segment of intestine without contact with food. This reduces both the amount of food that can be consumed and the absorption of calories and nutrients.

Mini gastric bypass is recognized by IFSO (International Federation for the Surgery of Obesity) as a standardized bariatric procedure, with growing evidence on its safety and efficacy in the medium and long term.

Benefits of Mini Gastric Bypass

In appropriately selected patients, mini gastric bypass may offer the following benefits:

• Significant weight loss: comparable to or slightly greater than traditional gastric bypass in many studies.
• Excellent metabolic control: significant improvement in type 2 diabetes, hypertension, dyslipidemia, and other obesity-related conditions.
• Simpler technique: with a single intestinal connection, the procedure is typically shorter and technically less complex than traditional bypass.
• Potential reversibility: the anatomy of the mini bypass allows, in selected cases, reversal or conversion of the procedure if necessary.
• Laparoscopic approach: performed through small incisions, promoting faster recovery.

Benefits and risks are reviewed individually. Long-term outcomes also depend on diet, physical activity, and ongoing medical follow-up.

Who Is a Candidate for Mini Gastric Bypass?

General candidacy criteria are similar to those for other bariatric procedures. Mini bypass may be especially considered for:

• Patients with BMI ≥35 kg/m², with or without obesity-related diseases.
• Patients with poorly controlled type 2 diabetes, where the malabsorptive component may provide additional metabolic benefit.
• Patients who require revision surgery after a gastric sleeve with insufficient results.
• Patients with very high BMI (>50), where the combination of restriction and malabsorption may be necessary to achieve adequate weight loss.

It is not the first choice in patients with a history of bile reflux or biliary tract disease. Dr. Monroy evaluates each case individually to recommend the safest and most effective procedure.

How Is Mini Gastric Bypass Performed?

The procedure is performed laparoscopically, under general anesthesia, through small incisions in the abdomen:

1. Creation of the gastric reservoir: the stomach is divided to create a long, narrow pouch, separated from the rest of the stomach.
2. Intestinal anastomosis: the gastric reservoir is connected directly to a loop of the small intestine, leaving a segment of intestine bypassed (generally between 150 and 250 cm, depending on the case).
3. Integrity verification: the connection is checked for tightness and the absence of leaks or bleeding.
4. Incision closure: the small incisions are closed at the end of surgery.

The procedure typically takes between 1 and 1.5 hours, though time may vary depending on each patient's anatomy and medical history.

Recovery After Mini Gastric Bypass

Recovery is progressive and similar to other laparoscopic bariatric procedures:

• Hospital stay of 1 to 2 nights.
• Progressive phased diet: clear liquids, full liquids, purees, soft foods, and finally regular meals.
• Return to daily activities within 2 to 3 weeks.
• Close nutritional follow-up, with emphasis on protein and supplementation of vitamins and minerals (iron, calcium, vitamin B12, vitamin D, among others).

Vitamin supplementation is particularly important after mini bypass, given the malabsorptive component. Periodic lab tests allow early detection and correction of deficiencies.

What is the difference between mini bypass and traditional gastric bypass?

The main difference is technical: traditional gastric bypass (Roux-en-Y) creates two intestinal connections, while mini bypass creates only one. This makes mini bypass a shorter procedure with less intestinal manipulation. Both offer similar results in weight loss and metabolic improvement. The choice between them depends on factors such as reflux history, patient anatomy, and surgical experience. Dr. Monroy will explain which is the best option for your case.

Is mini gastric bypass reversible?

Mini gastric bypass is potentially reversible or convertible, since the original stomach is preserved (no tissue is removed, unlike gastric sleeve). However, reversal is a complex procedure that is rarely performed. In practice, if needed, it is more common to convert to another type of procedure than to completely reverse the surgery.