A recent study found that obese or severely obese patients have a 60% higher risk of chronic diarrhea vs those who are within a normal weight range.
Obesity is associated with a significantly increased risk for abnormal bowel habits, according to a recent analysis of a nationally representative sample of the US adult population.
Obesity is known to increase patients’ risk for other health conditions (eg, heart disease, gastrointestinal disease, liver disease, diabetes), but less is known about the relationship between obesity and abnormal bowel movements.
Previous studies on this topic have lacked information on confounding factors that independently impact bowel habits. Because of this, researchers conducted a comprehensive analysis of the relationship between body mass index (BMI) and bowel habits (diarrhea, constipation, and normal).
The analysis controlled for dietary, lifestyle, psychological factors, and medical conditions.
"While several previous studies have pointed to an association between obesity and bowel habits, all lacked data on whether dietary or other factors drive the connection,” lead author Sarah Ballou, PhD, health psychologist, Division of Gastroenterology, Hepatology, and Nutrition, Beth Israel Deaconess Medical Center (BIDMC), Boston, Massachusetts, said in a BIDMC press release. “Our research confirms a positive association between obesity and chronic diarrhea and reveals for the first time that this relationship is not driven by confounding factors such as diet or physical activity level.”
The findings, published September 18 in Alimentary Pharmacology & Therapeutics, have important implications for how physicians might approach and treat symptoms of diarrhea in patients with obesity.
Using the 2009-2010 National Health and Nutrition Examination Survey, researchers analyzed the bowel health questionnaire responses of 5 126 patients aged >20 years with no prior history of irritable bowel syndrome, celiac disease, or colon cancer.
Ballou and colleagues compared the reported bowel habits of patients who had a BMI associated with being underweight (1.4%), normal weight (26.34%), overweight (33.77%), obese (21.4%), and severely obese (17.13%).
Up to 8.5% of obese and 11.5% of severely obese patients had chronic diarrhea vs 4.5% of patients with normal BMI.
Obese or severely obese patients were found to be at a 60% increased risk of having chronic diarrhea vs those with normal BMI after adjusting for demographic, psychological, lifestyle, and dietary factors, laxative use, and comorbid diabetes.
Also, after controlling for the same factors, the odds of severely obese patients having chronic diarrhea nearly doubled vs those with normal BMI. Authors note that these results show that the association between obesity and chronic diarrhea is not solely related to dietary factors and medical comorbidities.
Questions remain regarding what underlying causes could explain why obese patients are more likely vs those with normal BMI to have chronic diarrhea.
One possible explanation may be related to the link between obesity and chronic low-grade inflammation, which may contribute to diarrhea, the press release suggested.
How obesity triggers inflammation in the obese requires additional study, results of which could also inform clinical practice in this population.
“The treatment of obesity and obesity-related medical conditions requires multidisciplinary management,” senior author Anthony Lembo, MD, gastroenterologist, Division of Gastroenterology, Hepatology, and Nutrition, BIDMC, said in the same press release. “Clinicians should be aware of the relationship between obesity and diarrhea, especially considering the potential negative impacts altered bowel habits can have on quality of life.”