The overlap between irritable bowel syndrome, functional dyspepsia, and heartburn (gastroesophageal reflux disease [GERD]) seems to be a distinct entity that has a profile including sleep disturbance, psychological morbidity, and a surge in rates of atopy. Co-occurring (overlapping) irritable bowel syndrome, functional dyspepsia, and heartburn have been noted. But, if it is a distinct entity has not been established, nor what lifestyle, clinical, demographic, and psychological traits are linked with it.

Michael P Jones et al. undertook this study to determine the prevalence and temporal stability of this overlap and to recognize features specific to it in order to gain some insights into the potential etiopathogenesis. A total of 2 waves of a survey to a population-representative sample were carried out 3 years apart, enrolling 1312 people for this study. The chance-expected probability of complete overlap was calculated and compared with the observed complete overlap.

A range of demographic, lifestyle factors, medical diagnoses, sleep quality, and psychological distress were tested to identify predictors of overlap using logistic regression. In 2.1% (95% confidence interval 1.9, 3.7) of the sample, a complete overlap was noted and was closely replicated in wave 2 at 2.0%. The noted complete overlap was higher than anticipated by chance (0.2%) to a statistically meaningful extent.

Overlap between irritable bowel syndrome subtypes, functional dyspepsia subtypes, and heartburn was also elevated above chance expectation. Individuals with complete overlap were separately differentiated from others with respect to elevated rates of self-reported medically diagnosed asthma, elevated psychological distress score, and elevated impact on sleep quality. The discrimination provided by these factors was further independent of gender and age.