IBS Linked to Reduced Work Productivity in Japanese Workers

A longitudinal study published in BioPsychoSocial Medicine has identified a significant link between the presence of irritable bowel syndrome (IBS) and reduced work productivity among Japanese workers. The research, conducted by Nagisa Sugaya, Shuhei Izawa, and Takeshi Sasaki, tracked participants over a one-year period to determine how IBS and related cognitive-behavioral factors influence both abdominal symptoms and professional performance. The findings suggest that the mere presence of IBS at the start of the study was associated with greater productivity impairment one year later, highlighting the lasting impact of this gastrointestinal condition on the workplace.

The study aimed to move beyond cross-sectional designs by examining the temporal relationship between IBS, occupational stress, and work outcomes. Previous research had established associations between IBS and poor quality of life, sleep problems, and burnout, but causal or longitudinal relationships remained unclear. By following a cohort of workers over time, the researchers sought to understand whether specific cognitive or behavioral responses to IBS, as well as workplace stressors, could predict changes in productivity and symptom severity.

Participants were recruited through an online survey platform operated by Hamon Co., a marketing research firm in Yokohama, Japan. The initial survey, designated as Time 1, was conducted from October 5 to October 20, 2023. The study targeted workers aged 20 to 49 years who worked more than 30 hours per week and were not self-employed or business owners. A total of 1,062 participants met the inclusion criteria at Time 1, with 329 individuals meeting the diagnostic criteria for IBS and 733 not meeting the criteria.

To diagnose IBS, the researchers utilized the Rome IV Diagnostic Questionnaire, which assesses the frequency of abdominal pain and its association with defecation. Individuals reporting red flag symptoms, such as blood in the stool or unexplained weight loss, were excluded to ensure the sample consisted of functional gastrointestinal disorders rather than organic bowel diseases. A follow-up survey, Time 2, was conducted one year later, with responses obtained from 424 participants, including 114 in the IBS group and 310 in the non-IBS group.

The study employed several validated instruments to measure key variables. Work productivity was assessed using the Work Productivity and Activity Impairment Questionnaire-General Health (WPAI-GH), which calculates percentages of time missed and impairment while working. Abdominal symptom severity was measured using the IBS Severity Index (IBS-SI). Cognitive responses to symptoms were evaluated with the Cognitive Scale for Functional Bowel Disorders (CS-FBD), while behavioral responses were measured using the IBS-Behavioral Responses Questionnaire (IBS-BRQ).

Occupational stress factors were measured using the Brief Job Stress Questionnaire (BJSQ), focusing on job control, job overload, and support from supervisors and coworkers. Additionally, general psychological health was assessed using the Patient Health Questionnaire-9 (PHQ-9) for depression, the Generalized Anxiety Disorder-7 (GAD-7) for anxiety, and the Somatic Symptom Scale-8 (SSS-8) for physical symptom burden. These measures allowed the researchers to control for potential confounding variables in their statistical models.

Hierarchical multiple regression analysis revealed that the presence of IBS at Time 1 had a significant effect on presenteeism and overall work productivity impairment at Time 2. The study found that while IBS was associated with increased absenteeism over the year, the primary driver of productivity loss was the impairment experienced while actually working, rather than the days missed entirely.

In the subgroup of participants with IBS, the interaction between maladaptive cognition related to IBS and job control at Time 1 was significantly related to abdominal symptoms at Time 2. Specifically, the data indicated that IBS symptoms tended to be more severe when job control was low and maladaptive cognitions, such as the belief that pain would never go away, were high. However, the researchers noted that simple slope tests for this interaction did not reach statistical significance, suggesting that while a trend was observed, the evidence for this specific interaction is not definitive.

Despite the significant impact of IBS presence on productivity, the study found that occupational stress factors and IBS-related cognitive-behavioral variables did not show significant independent effects on work productivity impairment at Time 2 within the IBS group. Instead, general physical symptoms, as measured by the SSS-8, were significant predictors of productivity loss. This suggests that non-abdominal physical symptoms, which are common in individuals with IBS, may play a more direct role in reducing work performance than the specific cognitive or occupational stressors examined.

The researchers acknowledged several limitations in their study. The reliance on online surveys meant that random sampling was not possible, potentially affecting the representativeness of the sample. Additionally, a high dropout rate of nearly 58% at Time 2 could have influenced the findings, as those who completed both surveys tended to have better physical and mental health indicators than those who dropped out. The sex ratio was also imbalanced, with a higher proportion of women in the IBS group, which reflects the known higher prevalence of IBS among women in Japan.

Despite these limitations, the study provides valuable insights into the long-term effects of IBS on the workforce. The findings suggest that early intervention for IBS may be crucial to prevent future declines in work productivity. The authors propose that combining workplace improvements, such as increasing job control, with psychological approaches like cognitive-behavioral therapy could help workers with IBS maintain their health and professional performance. This integrated approach addresses both the physical and mental aspects of the condition, which are deeply interconnected through the brain-gut axis.

The study contributes to the growing body of evidence on the economic and social burden of IBS. By demonstrating that IBS presence is a predictor of productivity loss, the research underscores the need for employers and healthcare providers to recognize IBS as a significant factor in occupational health. Further research is needed to explore how specific workplace adjustments can be implemented to support workers with IBS and to better understand the complex interplay between physical symptoms, cognitive responses, and occupational stressors.

Beyond general productivity losses, the baseline clinical characteristics revealed a persistent disease burden coupled with minimal clinical engagement. Workers identified with irritable bowel syndrome reported experiencing gastrointestinal symptoms for an average of 9.4 years, with a standard deviation of 8.8 years. Despite this prolonged chronicity, only 1.4 percent of these individuals were actively receiving medical treatment for their abdominal complaints when surveyed. The researchers noted that occupational obligations may leave little time to access healthcare, underscoring the relevance of Japanese policy initiatives that promote fitness-to-work frameworks and support employees in balancing chronic therapy with employment duties. In establishing the cohort, screening evaluated participants across four clinical subtypes including constipation-predominant, diarrhea-predominant, mixed, and unclassified forms using the Bristol Stool Scale alongside the Rome IV criteria, while excluding candidates displaying red-flag symptoms such as nocturnal pain awakenings, unexplained fevers, rectal bleeding, or sudden weight reductions.

The longitudinal data also uncovered distinct absenteeism patterns and notable symptom fluctuations over the twelve-month observation window. Although the weekly recall measure detected relatively rare workplace absences, the broader annual evaluation indicated that health-related leave was significantly higher among employees with the gastrointestinal disorder. Specifically, 15.0 percent of workers with irritable bowel syndrome recorded more than seven days of health-related absence across the preceding year, compared to 6.6 percent of their unaffected colleagues, with 41 percent of absent individuals in the syndrome cohort attributing their time off directly to bowel difficulties. Concurrently, diagnostic status shifted considerably between survey rounds: 65.8 percent of participants who met the diagnostic criteria at baseline no longer satisfied the full threshold one year later, even though their self-reported symptom severity, maladaptive cognitions, and behavioral avoidance remained virtually indistinguishable from peers who maintained their diagnosis.

Workplace social dynamics displayed unexpected longitudinal associations with abdominal distress. Hierarchical regression analysis revealed that higher baseline support from supervisors and coworkers was significantly linked to greater abdominal symptom severity twelve months later. The authors suggested that workers enduring more severe or debilitating symptoms may have felt compelled to seek greater day-to-day assistance from colleagues, driving an apparent positive link over time, even while correlation analyses confirmed that robust workplace support was associated with lower subsequent depression and anxiety scores. Over the course of the follow-up year, participants across the entire sample experienced reductions in weekly working days and social support, accompanied by modest increases in work time missed due to illness.

These individual trajectories also mirrored broader societal transitions in post-pandemic Japan. The study noted that qualitative job overload among workers with the condition was significantly higher at baseline than at follow-up, whereas depressive symptoms improved significantly only among respondents without the disorder. The authors highlighted that the Japanese government reclassified COVID-19 as a Category V infectious disease in May 2023, prompting phased returns from telework to office commuting that may have imposed heavier qualitative burdens on employees managing bowel unpredictability. Compounding these dynamics, the study faced a 58 percent attrition rate between waves; dropouts were significantly younger and predominantly female, presenting with higher baseline depression, anxiety, physical symptom burdens, and job overload. Consequently, the investigators cautioned that selective retention of healthier respondents may have caused the longitudinal analyses to underestimate the full occupational consequences of the illness.

Subject of Research: Effects of irritable bowel syndrome and related cognitive-behavioral and occupational stress factors on the productivity and abdominal symptoms of Japanese workers: a longitudinal study

Article Title: Effects of irritable bowel syndrome and related cognitive-behavioral and occupational stress factors on the productivity and abdominal symptoms of Japanese workers: a longitudinal study

Article References: Sugaya, N., Izawa, S., & Sasaki, T. (2026). Effects of irritable bowel syndrome and related cognitive-behavioral and occupational stress factors on the productivity and abdominal symptoms of Japanese workers: a longitudinal study. BioPsychoSocial Medicine, 20(1), Article 2. https://doi.org/10.1186/s13030-026-00349-z

Image Credits: AI Generated

DOI: 10.1186/s13030-026-00349-z

Keywords: Effects, irritable, bowel, syndrome, related, cognitive-behavioral, occupational, stress, factors, productivity, abdominal, symptoms