Gastric bypass

With gastric bypass, food bypasses a large part of the intestine, and its absorption is greatly reduced. The intervention consists of creating a diversion between the stomach and the terminal part of the small intestine: the stomach is transformed into a pouch of 15–20 ml, and the path of the food is rerouted. The result is twofold — restricting the amount of food ingested and reducing its absorption — which makes the bypass the procedure with the highest success rate in eliminating excess kilograms.

Gastric bypass at a glance

• Type of procedure: restrictive and malabsorptive; performed exclusively laparoscopically, using minimally invasive methods
• Indications: advanced morbid obesity — body mass index over 50
• The ideal candidate: 18–65 years old, obese for at least 5 years, without alcohol problems and without untreated psychiatric conditions (such as depression)
• Reported results: 65–80% of excess weight lost at about one year
• Keep in mind: requires vitamin and mineral salt supplements long term

What is gastric bypass?

The surgical intervention consists of creating a diversion (bypass) between the stomach and the terminal part of the small intestine, creating an alternative section in which food absorption no longer takes place. In practice, the stomach is transformed into a small pouch, a transformation combined with a distal diversion of the food at the level of the small intestine.

The intervention thus simultaneously produces a restriction of the amount of food the patient ingests and a reduction of its absorption in the small intestine. For now, the gastric bypass procedure is performed only laparoscopically, using minimally invasive methods.

Who is it recommended for?

Gastric bypass is indicated for patients suffering from advanced morbid obesity — people with a body mass index greater than 50 — who need a significant reduction of excess weight in a relatively short time.

The ideal patient for this procedure has been obese for at least 5 years, has had no problems with alcohol or untreated psychiatric conditions (such as depression) and is between 18 and 65 years old.

How does the operation work, step by step?

1. Creating the gastric pouch — the upper part of the stomach is stapled and transformed into an upper pouch of about 15–20 ml, the rest remaining as the lower stomach.
2. Dividing the intestine — the small intestine is divided 50 cm from the duodenum.
3. The anastomosis — the end of the intestine is brought to the gastric pouch and sutured to it, creating a Y-shaped circuit, whose benefit relates to the degree of food absorption in the body.

How does it work after the operation?

The patient can eat small amounts of solid food, which are evacuated into the small intestine without reaching its areas of maximum absorption. The fact that the food bolus avoids a portion of the intestine is very beneficial for losing excess weight: far fewer calories are absorbed. From the small intestine, the food reaches the colon, and the indigestible remains are eliminated — digestion thus remains complete.

What are the advantages of gastric bypass?

• the highest success rate in eliminating excess weight (65–80% at about one year)
• improvement of certain medical conditions associated with obesity: hypertension, gastro-oesophageal reflux disease, back and joint pain, obstructive sleep apnoea
• other obesity-related conditions — such as venous thromboembolism and leg oedema — disappear entirely following a gastric bypass
• improvement of diabetes symptoms: blood sugar can drop without medication, and the disease can even go into remission
• the results of the intervention persist for many years after the operation

What is the recovery like, stage by stage?

• First days: liquids are consumed, but avoiding sweet liquids — these are absorbed quickly and can produce vomiting, diarrhoea and sweating (dumping syndrome).
• Next stage: semi-solid foods.
• After about 3 weeks: food can be chewed and swallowed normally, in small portions.
• Long term: it is recommended that the natural diet be combined with products containing mineral salts and vitamins, because the bypass, being an intestinal diversion intervention, can produce deficiencies over time.
• Physical energy: may be reduced after the intervention, due to the dietary restrictions and the general post-operative state; returning to normal energy levels may take about 3 months.

For optimal monitoring of the weight-loss process, good collaboration between patient and doctor is needed. The goal is a gradual loss of the excess kilograms — losing weight too fast can create major health risks.

Frequently asked questions

Who is a candidate for gastric bypass?

Patients with advanced morbid obesity (BMI over 50), aged between 18 and 65, obese for at least 5 years, without alcohol problems and without untreated psychiatric conditions. The final evaluation belongs to the doctor.

What is dumping syndrome?

The body’s reaction to sweet foods or liquids absorbed too quickly after the bypass: vomiting, diarrhoea, sweating. It is prevented by avoiding concentrated sweets, especially in the post-operative period.

Why are supplements necessary?

Because the bypass is an intestinal diversion intervention: food bypasses the areas of maximum absorption, so vitamin and mineral salt deficiencies can appear over time. Supplementation, established by the doctor, prevents these deficits.

Bypass or gastric sleeve?

The bypass offers the greatest weight loss and strong metabolic benefits (including diabetes remission), but involves an intestinal diversion and long-term supplements. The sleeve keeps the normal digestive path and nutrient absorption. See all bariatric procedures.