Obesity is the 21st century pandemic. By 2025 6 % of men and 9 % of women will suffer from morbid obesity. For morbid obesity bariatric surgery is the main treatment option. The presence of pathology of the upper gastrointestinal tract (GERD) determines the choice of surgical intervention. The study involved 68 patients 47.1 ± 10.2 years with morbid obesity. Patients had the following gastroenterological pathologies: erosive esophagitis – 6 (8.8 %), hiatal hernia – 9 (13 %), erosive and ulcerative lesions of the stomach and duodenum – 13 (19 %). Heartburn disturbed 38 (55 %), regurgitation – 17 (25 %), severity and feeling of fullness in the epigastrium – 29 (42 %), pain or burning in the epigastrium – 8 (11 %) patients. Fifty (73.5 %) patients underwent laparoscopic sleeve gastrectomy, 18 (26.5 %) patients – laparoscopic Roux-en-Y gastric bypass. Comprehensive preoperative examination (x-ray of the upper gastrointestinal tract with barium, daily pH impedance measurement, esophageal manometry) and phenotyping of GERD lead to reduction of GERD symptoms in patients with morbid obesity after sleeve gastrectomy.