High Prevalence of Disorders of Irritable Bowel Syndrome and Functional Dyspepsia in Night Shift Workers: A Cross-Sectional Study in Australia and the United Kingdom.

BACKGROUND & AIMS: Night shift work disrupts circadian rhythms and may contribute to gastrointestinal (GI) symptoms. The aims were to assess the prevalence of irritable bowel syndrome (IBS) and functional dyspepsia (FD) in night shift workers, evaluate their impact on quality of life, and examine associated dietary patterns and intake.

METHODS

We conducted a cross-sectional study of night shift workers (≥8 shifts/mo between 11 pm and 3 am) in Australia and the United Kingdom from March to July 2024. Participants completed validated questionnaires including Rome IV criteria for IBS and FD, IBS Severity Score System (IBS-SSS), Leuven Postprandial Distress Scale (LPDS), IBS Quality of Life (IBS-QoL), Visceral Sensitivity Index (VSI), Depression Anxiety Stress Scale-21 (DASS-21), and Comprehensive Nutrition Assessment Questionnaire (CNAQ).

RESULTS

Among 392 participants (69.9% female, median age 48 years), 21.3% met Rome IV criteria for IBS, 30.4% for FD, and 24.5% for both conditions. Significantly more females met criteria for both disorders (P < .05). Participants with IBS and/or FD reported significantly higher IBS-SSS, LPDS, VSI, and DASS-21 scores compared with those without (all P < .001). Most participants (59.9%) reported night shifts negatively affected their GI symptoms, and 16.3% considered changing jobs due to symptoms. Medication use was higher in those with IBS/FD (41% vs 17%; P < .01). No significant differences in dietary patterns were observed between groups.

CONCLUSIONS

Night shift workers have a substantially higher prevalence of IBS and FD compared with reported general population rates, with significant impacts on IBS-specific quality of life and mental health. These findings highlight the need for targeted interventions to support gastrointestinal and mental health in this vulnerable working population.