Gastric Bypass
A gastric bypass makes your stomach smaller and reduces how much food your body absorbs, for significant and lasting weight loss. It is suitable if your BMI is over 40, or over 35 with diabetes or high blood pressure. It is the technique of choice if you have diabetes: it changes the hormones your gut produces, which can make diabetes go away. Dr. Jesús Lago operates at Clínica 3 de Mayo in Madrid, for patients from the UK, Ireland and beyond.
- All-inclusive price
- €11,950
- Hospital stay
- 72 h
- Recovery
- 10 to 12 days
How Gastric Bypass Works
Both techniques connect a small stomach pouch to a lower section of the intestine, so food no longer passes through the first part of the gut. Roux-en-Y adds a second connection further down. BAGUA uses just one, without dividing the intestine. The price, hospital stay and recovery are the same for both.
The first connection links the small stomach pouch to the intestine. A second connection, further down, rejoins the bypassed section of intestine so that digestive juices can mix with food.
- Duration
- 2 to 4 h
- Approach
- Laparoscopic (small incisions)
- Hospital stay
- 72 h
- Anesthesia
- General
- Recovery
- 10 to 12 days
We leave a small stomach of around 100 ml and connect it to the intestine at a single point, without dividing the intestine or the tissue that supports it (the mesentery). With only one connection, the operation takes about two hours.
- Duration
- 2 h
- Approach
- Laparoscopic (small incisions)
- Hospital stay
- 72 h
- Anesthesia
- General
- Recovery
- 10 to 12 days
Our Complication Rates
We carry out more than eight bypass operations a year, Roux-en-Y and BAGUA combined. These figures come from Clínica 3 de Mayo's retrospective review of the last ten years, updated in September 2026.
| Complication | Published literature* | Clínica 3 de Mayo |
|---|---|---|
| Overall rate | 10-20% | 7.2% |
| Major | 3-8% | 1.1% |
| Suture leak | 1-2% | 0.2% |
| Anastomotic stricture | 3-8% | 3.1% |
| Marginal ulcer | 2-10% | 3% |
| Thromboembolism | 0.3-1% | 0.5% |
| Internal hernia | 1-5% | 0.1% |
- * Peterli R et al., SM-BOSS, JAMA, 2018.
- * Salminen P et al., SLEEVEPASS, JAMA Surg, 2022.
- * Arterburn DE et al., JAMA, 2020.
These rates apply to the Roux-en-Y bypass. We do not publish a complication table for the one-anastomosis bypass (BAGUA).
Frequently Asked Questions
The price of a gastric bypass covers your preoperative assessment, evaluation consultation, surgery, hospital stay and follow-up appointments. It also includes two years of nutritional follow-up, weight loss surgery aftercare with two appointments with a psychologist, and a 24-hour emergency line for two years. If needed, it also covers an endoscopy, a blood test and an ultrasound.
Both types of gastric bypass work in the same way: they reduce the stomach and bypass part of the intestine. Roux-en-Y uses two connections and BAGUA just one, so the operation is shorter. In BAGUA, as in SADI-S, the section of intestine that absorbs food after the connection is shorter than in Roux-en-Y. That is why these two techniques lead to greater weight loss. Recovery, hospital stay and price are the same for Roux-en-Y and BAGUA.
See SADI-SGastric bypass is for patients with a BMI over 40, or over 35 with diabetes or high blood pressure. At Clínica 3 de Mayo, this is the highest threshold of our three weight loss procedures.
Yes, there is a risk, because a gastric bypass reduces how much food your body absorbs. That is why the price includes two years of nutritional follow-up. We go through the supplements you will need at your evaluation consultation.
Dumping syndrome is a group of digestive symptoms (nausea, palpitations, feeling unwell) that can occur after a gastric bypass. It is triggered by a meal that is too sugary or too fatty, when food moves too quickly from the stomach into the intestine. We give you simple dietary guidance to help you avoid it.
We treat it at Clínica 3 de Mayo, and any further surgery is included. A leak is digestive fluid escaping through a suture line in the stomach or intestine after a gastric bypass. In rare cases, a serious leak means we transfer you to a public hospital for immediate treatment.
A gastric band narrows the stomach without altering it. A gastric sleeve makes it permanently smaller, with no device left inside. A gastric bypass goes further, adding an intestinal bypass that also reduces how much food your body absorbs.
See the gastric sleeveAfter a gastric bypass, the price includes two years of nutritional and bariatric follow-up. After that, you can keep coming to Clínica 3 de Mayo for your checkups.
Traveling from Abroad for Surgery
If you are coming from abroad, we organize your stay in Madrid and handle your follow-up remotely.
The Medical Team
Dr. Jesús Lago, lead surgeon in practice since 2000, heads a team that has worked together for almost a decade at Clínica 3 de Mayo. All our doctors are fully qualified and registered with the Madrid College of Physicians (Colegio de Médicos de Madrid).
- Dr. Jesús LagoLead surgeon and president of SETIO (Spanish Society for Interventional Obesity Techniques)
- Dr. Iordan Minchev IordanovHead of anesthesia and team coordinator
- Dr. Werner Engel EspinosaAnesthesiologist
- Dr. Sara Vázquez AmigoCoordination and follow-up
- Dr. Álvaro Henríquez DaoAssistant surgeon
- Gonzalo Chorén PiermateiNurse
Our Centers
Clínica 3 de Mayo Hospital Fuensanta
Calle Arturo Soria 17, 28027 Madrid
Where your operation takes place. Operating rooms, inpatient ward, 24/7 emergency department, intensive care.
Consultations and follow-up
Clínica 3 de Mayo · Calle Apodaca 4, 28004 Madrid
Also at the Hospital Fuensanta outpatient clinic on Thursdays.
Clínica 3 de Mayo S.L. · CIF B83091363
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We reply within 24 hours on weekdays, then see you for a first consultation by video call or in Madrid.