Super Obesity, i.e. a BMI above 50, is difficult to treat. Normal gastric bypass surgery is not always enough for proper weight control. Bypassing a longer segment of the gut may be more beneficial. Which part to bypass is not clear.

The investigators want to compare the effects between preventing a 60 cm proximal (oral) portion of the jejunum from food contact with the effects when preventing a 200 cm part of the jejunum from contact with bile and pancreatic juice.

Endpoints are quality of life, gastrointestinal function, and weight development.

Two variations of gastric bypass are compared:

Method 1 (test method):A 200 cm BP-limb (distance Treitz to EA) + 150 cm common channel (EA to ileocecal valve) + Roux-Y-limb variable Method 2 (standard method): A 60 cm BP limb + 150 cm Roux-Y-limb + common channel variable.

Patients are evaluated according to the principles of the Scandinavian Obesity surgery registry (SOReg) with the addition of two additional questionnaires.

FU time is set at 5 years.

Inclusion Criteria:

• BMI 50-65
• Age 18-55
• Conservative attempts at weight reduction failed

Exclusion Criteria:

• Inability to speak and understand the Swedish language
• Residence outside the county of Skåne
• Psychotic disease
• Inflammatory bowel disease

Randomisation in the OR, (closed envelopes, blocks of six) no further info to ward or follow-up unit. No specific info as to randomisation outcome given to patients, all patients follow same protocol.

Code number in operative charts.