Relationship of work schedules to gastrointestinal diagnoses, symptoms, and medication use in auto factory workers.

BACKGROUND Gastrointestinal (GI) complaints are common in shift workers. This study examines the relationship between work schedules and GI symptoms, medications, and diagnoses. METHODS In a cross-sectional survey of 343 US auto factory workers, four work schedule variables were examined: assigned shift, number of hours worked, number of night hours, and schedule variability. Multiple regression tested the relationship between GI outcomes and work schedule variables while controlling for covariates. RESULTS The evening shift was associated with more GI symptoms and GI diagnoses. Unexpectedly, more consistent work times were associated with having a GI diagnosis. As schedule variability increased the probability of GI medication use increased in low noise exposure. CONCLUSION Findings suggest that evening shift and widely varying work start and end times may increase risks for GI disturbances.