[Disaccharidase deficiency and functional bowel diseases].

Aim. To elucidate the role of intestinal carbohydrases (glucoamylase, maltase, sucrose, and lactase) in the etiology and pathogenesis of functional bowel diseases (FBD). Subjects and methods. 74 patients (36 men and 38 women) aged 18 to 50 years with FBD were examined. According to Rome IV criteria (2016), there was diarrhea-predominant irritable bowel syndrome (IBS) in 21 patients, functional diarrhea (FD) in 33, constipation-predominant IBS in 6, functional constipation (FC) in 4, and mixed IBS in 10. The activity of carbohydrases in the small intestine mucosa (SIM) was investigated by the Dahlquist method modified by Trinder in the duodenal biopsy specimens obtained during esophagogastroduodenoscopy. Results. Lactase deficiency was identified in 87.8% of the patients; maltase deficiency in 48.6%; sucrose deficiency in 51.3%; and glucoamylase de ficiency in 85.1%. The activity of all the investigated enzymes was reduced in 23 (31.1%) patients with FBD; deficiency of 1-3 carbohydrases was found in 47 (63.5%). Normal enzymatic activity was established in 4 (5.4%) patients. Conclusion. In the majority of patients with FBD, the intestinal symptoms are caused by the decreased activity of SIM carbohydrases. Therefore, disaccharidase deficiency associated with an established damaging agent (nonsteroidal anti-inflammatory drugs, antibiotics, acute intestinal infections, etc.) should be considered to be a more precise diagnosis.