To evaluate the effectiveness of enteroprotector Rebamipide in the treatment of enteropathy with impaired membrane digestion (EIMD). We examined 102 patients aged 18 to 50 years (41 men and 61 women) with clinical signs of irritable bowel syndrome (n=65), functional diarrhea (n=33), and functional constipation (n=4) according to Rome IV criteria (2016). The activities of glucoamylase (GA), maltase, sucrase and lactase were determined by Dahlquist-Trinder method in duodenal biopsies obtained during esophagogastroduodenoscopy. The control group consisted of 20 healthy people aged 23-47. They showed following average enzyme activity: lactase - 42±13 ng glucose on 1 mg of tissue per minute, GA - 509±176, maltase - 1735±446, sucrase - 136±35 ng glucose on 1 mg of tissue per minute. These numbers were taken as the norm. The activity of the disaccharidases was reduced in 89.2% out of 102 patients, and they were diagnosed with EIMD. Thirteen patients with EIMD were recommended to maintain the FODMAP diet and take enteroprotector Rebamipide 100 mg 3 times a day for 12 weeks. After 3 months 11 patients reported decreased or no flatulence, abdominal pain, stool disorder; 2 patients reported no change. The activity of GA increased to an average of 149±82 (by 78%, p=0.016), maltase - to 864±472 (by 131%, p=0.0019), sucrase - 63±35 (by 95%, p=0.0041) and lactase - 10±8 ng glucose on 1 mg of tissue per minute. The activity of lactase did not change. We discovered a previously unknown phenomenon of the disaccharidases activity increase in duodenal mucosa and improved carbohydrates tolerance in the patients with EIMD taking Rebamipide in the dose 300 mg/day for 12 weeks.