Functional gastrointestinal disorders (FGID) such as diarrhoea and constipation can reflect intestinal dysfunction, especially with regard to intestinal microbiota, which, in turn, have been associated with chronic conditions, including obesity and insulin resistance. However, little is known of the association between FGID and type 2 diabetes (T2D) risk.

This analysis aimed to determine the influence of diarrhoea, constipation and alternating bouts of diarrhoea/constipation on T2D risk in 62,683 women from the prospective E3N–EPIC cohort.

A total of 1795 T2D cases were recorded during follow-up. Compared with women who had normal gastrointestinal transits, women with chronic diarrhoea or alternating diarrhoea/constipation were at increased risk of T2D (HR: 1.29, 95% CI: 1.00–1.65 vs. HR: 1.32, 95% CI: 1.15–1.52, respectively), whereas women with constipation had a decreased risk (HR: 0.67, 95% CI: 0.57–0.78). There was no interaction between FGID and body mass index for risk of T2D. Also, these associations were independent of dietary habits such as coffee, fruit and vegetable consumption, and even of the use of laxatives and psychotropic drugs.

The present analysis showed, for the first time, a limited association between FGID and T2D risk in a large prospective cohort, and supports the hypothesis of a relationship between gastrointestinal function and diabetes. The presence of gastrointestinal transit disorders may assist in screening for subjects at higher risk of diabetes beyond the conventional risk factors.