Currently, one anastomosis gastric bypass (OAGB) or mini-gastric bypass (MGB) is a common bariatric procedure for treating obesity. Weight gain after surgery is a big problem in bariatric practice. Therefore, adjustable bands and rings are used, for example, "FobiRing". But foreign material can cause complications - the erosion of the stomach wall. For this reason, surgeons avoid the use of various mechanical devices on living tissues.

The greatest criticism is of the OAGB for the likelihood of biliary reflux. In case of reflux of bile into the esophagus after surgery, as a rule, a second operation is required with conversion OAGB to the Roux-en-Y method.

In addition, along with obesity, gastroesophageal reflux disease (GERD) are steadily increasing world weight and antireflux surgery must be performed simultaneously with bariatric surgery in obese patients. In these cases, most often in bariatric practice, hiatus cruroraphy is performed, and less often fundoplication using the fundus of the excluded part of the stomach.

We hypothesize that total fundoplication can not only treat GERD but also significant prevent the return of weight like after a banded gastric bypass and prevent postoperative bile reflux in the esophagus.

The aim study is to compare primary outcome as weight loss after total wrapping of the fundus of the gastric excluded part (FundoRing) and non - wrapping (non - banded) standard method of laparoscopic one anastomosis gastric bypass and measure secondary outcome: bile reflux in the esophagus and GERD symptoms.

Methods: Adult participants (n=1000) are randomly allocated to one of two groups:

Experimental surgical bariatric procedure in the first (A) group: patients (n=500) undergo the laparoscopic one anastomosis gastric bypass with the total wrapping of the fundus of gastric excluded part and suture cruroplasty if present hiatal hernia (FundoRingOAGB group); Active comparator surgical bariatric procedure in the second (B) group: patients (n=500) undergo the laparoscopic one anastomosis gastric bypass and with only suture cruroplasty if present hiatal hernia (OAGB group).

One anastomosis Gastric Bypass/Mini Gastric Bypass (OAGB/MGB) is gaining popularity as a primary surgical treatment for morbid obesity.

The aim study is to compare primary outcome as weight loss after total wrapping of the fundus of the gastric excluded part (FundoRing) and non - wrapping (non - banded) standard method of laparoscopic one anastomosis gastric bypass and measure secondary outcome: bile reflux in the esophagus and GERD symptoms.

Methods: Adult participants (n=1000) are randomly allocated to one of two groups:

Experimental surgical bariatric procedure in the first (A) group: patients (n=500) undergo the laparoscopic one anastomosis gastric bypass with the total wrapping of the fundus of gastric excluded part and suture cruroplasty if present hiatal hernia (FundoRingOAGB group); Active comparator surgical bariatric procedure in the second (B) group: patients (n=500) undergo the laparoscopic one anastomosis gastric bypass and with only suture cruroplasty if present hiatal hernia (OAGB group). All patients are then followed up 12, 24, 36 months after surgery where record the changing body mass index and and measure secondary outcome: bile reflux in the esophagus and GERD symptoms.

Inclusion Criteria:

• BMI from 30 to 50 kg / m2.
• The person is generally fit for anesthesia (ASA grading 1-2) and surgery.
• The person commits to the need for long-term follow-up.

Exclusion Criteria:

• BMI less than 30 kg / m2 and more than 50 kg / m2.
• Prosthetic (mesh) Hiatal herniorrhaphy or large hiatal hernia;
• Esophageal shortening
• Los Angeles Classification of Oesophagitis (LA grade) C or D reflux esophagitis
• History of surgery on the stomach or esophagus
• Less than 18 or more than 60 years of age
• Not fit for bariatric surgery
• Psychiatric illness
• Patients unwilling or unable to provide informed consent