The capacity of the stomach is reduced in the same way as a sleeve operation.

Then the small intestine is altered so that food is not digested in the duodenum by the secretion of bile (product of the liver) and the pancreas (enzymes for the digestion of proteins, fats and sugars).

The intestine is divided in two almost equal segments. The first segment (biliopancreatic) is kept intact as from the duodenum but the latter is separated from the stomach and is closed off. The second half is reconnected directly to the gastric tube (sleeve). This is the food segment because the food in-take passes through it.

The two segments are reunited in such a way that food and digestive enzymes are mixed only in one metre of the small intestine (common limb) producing reduced digestion in a short intestinal fraction.

This typical mixed operation (restrictive by the sleeve and malabsorptive by the shortening of the intestine to one metre through which food and digestive enzymes pass) is suitable for patients with a very high BMI (higher than 50) or for those who could not accept psychologically to eat reduced quantities of food.

The malabsorption means lifelong taking of vitamin supplements, if not, dangerous deficiencies occur