The role of arousal in maintaining the relationship between insomnia and gastrointestinal conditions.

The relationship between gastrointestinal (GI) conditions and sleep disturbance has been well established. With a higher-than-average prevalence of sleep disturbance in individuals with GI conditions, it is imperative to better understand the maintaining factors driving this comorbidity. Although there are separate, ongoing investigations into both the biological mechanisms and interventions for the sleep and GI relationship, there is a considerable need to further specify common and mutually influential pathways. In our review, we highlight arousal as both a unifying feature of insomnia and various GI conditions as well as a possible mechanism for action for the bidirectional relationship. This review aims to summarize the relationship between arousal, insomnia, and GI conditions, specifically examining sources of arousal across four broad domains: psychosocial factors, physical health factors, daily living factors, and sociocultural factors. Online databases, including PubMed, PsychInfo, and Google Scholar, were searched for full-text English language articles focused on patients with insomnia and/or GI conditions and involving mental health, physical comorbidities, and social factors. Understanding the nature of this bidirectional relationship between sleep and GI through the lens of arousal as a common mechanism will lend itself to using a multidisciplinary approach to treatment and care.