Obesity carries increased diarrhoea risk

Obesity appears to have a positive association with chronic diarrhoea, independent of several known confounding factors, as shown in a study.

Researchers used data from the 2009–2010 National Health and Nutrition Examination Survey and identified 5,126 respondents who completed the bowel health questionnaire (BHQ), were ≥20 years of age, and had no prior history of inflammatory bowel disease, coeliac disease or colon cancer.

Of the respondents, 70 (1.40 percent) were underweight, 1,350 (26.34 percent) were normal weight, 1,731 (33.77 percent) were overweight, 1,097 (21.40 percent) were obese and 878 (17.13 percent) were severely obese.

Chronic diarrhoea was present in 8.5 percent of obese and 11.5 percent of severely obese individuals as compared to only 4.5 percent of normal weight individuals. Stepwise regression showed severe obesity to be independently associated with increased risk of diarrhoea. Factors such as dietary, lifestyle, psychological and medical comorbidities were included in the analysis as potential confounders.

The present data indicate that the risk of diarrhoea increases with severity of obesity, the researchers said. Future studies should explore the underlying physiologic mechanisms of the association between obesity and chronic diarrhoea.

While not clearly understood, the mechanisms by which obese individuals are likely to have chronic diarrhoea may involve bile acid malabsorption, faster colonic transit, and increased intestinal permeability, microbial dysbiosis and endotoxemia (ie, increased levels of lipopolysaccharide).  [Aliment Pharmacol Ther 2013;38:967‐976; Am J Physiol Gastrointest Liver Physiol 2008;295:G382‐388; Int J Endocrinol 2018;2018:4095789]