Association between frailty and chronic constipation and chronic diarrhea among American older adults: National Health and Nutrition Examination Survey

BACKGROUND: This study was to explore the relationship between chronic constipation, chronic diarrhea, and frailty in older Americans. METHODS: This cross-sectional study selected a total of 4241 community-dwelling individuals aged 60 years and older from the 2005–2010 National Health and Nutrition Examination Survey. Frailty was measured using a 49-item frailty index, and a frailty index > 0.21 was defined as a frail status. Chronic constipation and chronic diarrhea were defined as the “usual or most common type of stool” by the Bristol Stool Form Scale (BSFS) Types 1 and 2 and BSFS Types 6 and 7, respectively. Weighted logistic regression analysis was used to examine the relationship between gut health and frailty status. Restricted cubic spline (RCS) curves were built to assess the association between frailty index and stool frequency. RESULTS: Frailty status was associated with higher odds of constipation in an unadjusted model; however, after further adjusting for confounding variables, the relationship between frailty status and constipation was not statistically significant. We discovered a positive correlation between the frailty status and diarrhea after adjustment for all variables. The frailty index showed a U-shaped relationship with stool frequency, and the frailty index was the smallest at a frequency of 10 stools/week. CONCLUSION: Negative associations were observed between frailty status and chronic constipation and diarrhea among older adults. Older adults who have a bowel movement frequency of about 10 times per week are the least frail. Future studies are warranted to confirm the causal relationship in this association. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-023-04438-4.