Obesity and functional bowel disorders in adolescents: a pilot study

Background: Studies of the relationship between obesity and functional bowel disorders, carried out in different age groups, provide conflicting results. It remains unclear what factors are responsible for the transition from a tendency to constipation in children to a tendency to diarrhea in adults with obesity.Aim: To establish factors related to stool consistency as a surrogate marker of colon transit in adolescents with obesity.Materials and methods: A single-center observational cross-sectional study was carried out. We consecutively recruited adolescents, aged 11–17 years with obesity. Socio-demographic characteristics, lifestyle and nutritional characteristics were assessed using questionnaires. Bowel symptoms were assessed using questionnaires and interviews. Stool consistency was assessed using the Bristol Stool Form Scale. Serum concentrations of ALT, AST, bilirubin, cholesterol, glucose, HbA1c, leptin, and insulin were determined. The HOMA-IR index was used to determine insulin resistance.Results: One hundred and ten adolescents with obesity were enrolled in the study. Of these, 69.1% had a pathological consistency of feces, with the prevalence of forms characterizing delayed gut transit (49.1%). The predominance of loose stools was reported by 5.5% of patients. The combination of different forms of stool (unstable stool) was described by 14.5% of adolescents. Hard stools were common among adolescents from single-parent families and adolescents who rarely consume dairy products. The presence of loose stools has been associated with insulin resistance.Conclusion: Most obese adolescents who do not have abdominal complaints have colon transit disorders. Medical professionals should actively ask these patients about stool frequency and properties. With constipation, dietary correction is justified. Research is needed to investigate in-depth gut microbiota as a possible link between obesity and diarrhea.