Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder. While ionizing radiation exposure, and its associated cancer risk, is well-studied in other GI disorders, there is a paucity of data in the IBS population.
After IRB approval, a retrospective cohort study at a tertiary care referral center was conducted. Radiologic studies performed between Jan 2008-Dec 2017 on patients diagnosed with IBS were retrospectively evaluated. Data from patients whose primary care physician and gastroenterologist were in our healthcare system were included. Analyses was performed by chi square and Mann Kendall trend test and multivariable logistic regression was applied to assess independent associations. Percentage of participants receiving more than a cumulative dosage of 50 mSv (consensus threshold for high cancer risk) in the study period was calculated
The mean age of participants was 40.83 years (SD: 12.12 years). 35.24% participants had a smoking history. A vast majority of participants were female (77.53%) and 55.95% of participants had a co-morbid psychiatric diagnosis. Most participants (85.46%) were on pain medications in the outpatient setting. 16 patients (7%) did not undergo any radiological study during the study period. 56 patients (24.67%) received greater than 50 mSv of cumulative effective radiation dosage during the 10-year study period. Mean yearly effective radiation dosage was 3.75 mSv per year (SD: 5.67). Mean cumulative effective radiation dosage during the study period was 37.45 mSv. A mean dosage of 27.87 mSv was attributable to studies involving the abdomen. Participants received a mean dosage of 17.59 mSv before and 19.86 mSv after the definitive diagnosis by the digestive disease clinic. Female gender, comorbid depression and anxiety, and diarrhea predominant IBS phenotype was significantly associated with an increased risk of radiation exposure (P < 0.05). Mann Kendall trend test did not reveal any change in average ionizing radiation exposure in patients during the study period (P > 0.05).
Previous limited data from Europe hinted at a low risk of radiation exposure in IBS but we finds that, contrary to popular belief, a significant proportion of IBS patients are exposed to high levels of ionizing radiation, which potentially poses a significant cancer risk. Nationwide cohort studies are needed to assess this risk and quality improvement initiatives are needed to decrease radiation exposure in this relatively young population.