Are We Overradiating Patients with Irritable Bowel Syndrome?

Introduction: Protracted exposures to small doses of radiation, even cumulative effective doses (CED) as low as 50-100 mSv, may increase the risk for malignancy. Medical radiation exposure has not been rigorously examined for patients with irritable bowel syndrome (IBS). We examined medical radiation exposure in patients with IBS at a tertiary care center in the USA.

Methods: Patients diagnosed with IBS at our institute from 2009 to 2018 were included in a retrospective cohort study. Medical charts were examined to calculate total and annual CED.

Results: 221 patients were included; mean CED was 40.32 mSv (SD: 54.36). Fifty-nine participants (26.7%) received >50 mSv of CED with 27 participants (12.2%) exceeding 100 mSv. Conventional imaging, nuclear medicine, and fluoroscopy accounted for 74.08, 12.93, and 12.98% of total CED, respectively. CT scans contributed to 66.61% of total CED. Outpatient orders accounted for 37.96% of total CED, while 31.4% of total CED was ordered in the emergency department. Population-specific high total CED was calculated as 105.65 mSv. Multivariable binomial logistic regression model found that comorbid anxiety, chronic pain medication use, and diarrhea-predominant IBS were independently positively associated with population-specific high CED exposure. No significant temporal trend in peri-diagnostic mean CED was found.

Conclusion: Patients with IBS receive high amounts of medical radiation, with 1 in 4 patients reaching at-risk levels of 50 mSv or more. Usage of pain medication at home, comorbid anxiety, and IBS-D are independently linked to an increased risk of high CED.