This study is the first to identify interesting and relevant descriptions to PCP and GP knowledge and treatment of PI-IBS. Overall, we found a wide range of understanding of which common foodborne pathogens can lead to functional gastrointestinal disorders such as PI-IBS. Awareness of PI-IBS as a phenomenon is present in a majority, but less than half of the physicians surveyed would discuss this as a possible outcome in their infectious GI patients. Given the known frequency of PI-IBS after GI infections, universal discussion with the patient of chronic consequences may be important.
The estimate that 42% of new IBS diagnoses are suspected to have a post-infectious etiology is higher than has been previously reported [2]. It may be that as awareness of PI-IBS among physicians has grown, more providers are taking detailed histories of antecedent acute GI illness and identifying a higher proportion of patients with such a trigger. Alternatively, the sample selection may have been biased or the survey design led respondents to inflate estimates of an infectious trigger. While most physicians agreed that knowing a patient had a previously diagnosed foodborne infection would change the way they approached treatment of their patients IBS, we did not ask how it would change their approach or how often they find a result. Given that there are no targeted therapies for PI-IBS at this time, we expect treatment should not change from IBS recommendations. However, it is possible that the time from diagnosis to treatment for the patients IBS may be shorter as there would be less diagnostic work-up to rule out potential etiologies.
In our survey, physicians frequently prescribed a probiotic for therapy. This management approach is not consistent with current guidelines for practice. The American College of Gastroenterology guidelines give the following recommendation, “We suggest probiotics, taken as a group, to improve global symptoms, as well as bloating and flatulence in IBS patients. (Recommendation: weak; Quality of evidence: low)”. Similarly, the Canadian Association of Gastroenterology states, “We suggest offering IBS patients probiotics to improve IBS symptoms (GRADE: Conditional recommendation, low-quality evidence)” [10]. While these recommendations don’t discourage use of probiotics, we are unsure why there is an observed practice variation between current practice guidelines and reported practice of this sample population. It is possible that patients are driving demand for probiotics based on their review and awareness of medical information from online sources and marketing. Most probiotics are OTC and, thus, it could be that while physicians did not recall them as often in the list of common medications they prescribe (as seen in our results for Table 2) physicians are supportive in recommending OTC probiotics for therapy when patients ask. In any case, given the lack of evidence for probiotics in the effectiveness of IBS therapy [11] physicians may not be fully helping their patients to avoid the excess costs (most often out of pocket) associated with therapies that lack proven effectiveness.
Interestingly, the estimate that roughly 4 out of 10 patients who develop PI-IBS will continue to have symptoms throughout their life is an important observation. Reported literature have only followed up subjects for up to 8 years [12]. To determine the prevalence of PI-IBS among Walkerton Health Study participants, 28.3% (n = 210) of patients enrolled into the PI-IBS cohort reported the condition after 2–3 years. At the 8-year follow-up, the overall prevalence within the cohort dropped to 15.4%, but over 50% of those diagnosed at year 2–3 were still symptomatic at year 8. These findings are consistent with the estimates given in this survey. While there exist no studies that have estimated the lifelong impact of PI-IBS, for some, IBS remains a chronic condition.
In addition to management, this survey focused on providers’ assessment of the functional impact associated with PI-IBS. While there may be cognitive bias (e.g. physicians will often focus on the more severe patients as representative of the general population of patients), the sample respondents describe significant impacts for the PI-IBS patient populations they manage. Because quantitative techniques may not be feasible in measuring symptom management, quality of life assessments remain an imperative aspect in follow up care among this patient population. In this sense, physicians will be able to gain a better understanding of treatment efficacy based on quality of life discussions prior to and during the treatment course. Buono et al. [13] found that patients with IBS-D reported significantly lower health-related quality of life than controls; these findings are consistent with our response from physicians. For example, physicians from our survey estimated an average loss of 10 h per week in their patients suffering from IBS, and also noted multiple employment-based impacts on quality of life due to their symptoms (Table 3). Buono et al. [14] found IBS-D patients had a 20.7% productivity loss compared to controls and had a significant daily activity impairment (29.5%) whereas Tack et al. [15] found those with IBS-C had a 27.7–51.5% productivity loss and an overall daily activity impairment from 36.4–56.8%. By discussing baseline symptoms and impacts on quality of life and subsequently comparing original answers to those after starting the treatment course, physicians can more easily recognize whether treatment is alleviating or aggregating symptoms [16].
In addition to an assessment of psychological and social impacts on patient life, it is important to address the economic burden incurred due to this chronic disease. The physicians in our survey estimated the average patient incurs $100–500 USD (40%) or $500–1000 USD (38%) in out-of-pocket expenses during the course of their illness which can be a significant financial burden for some. Buono et al. [14] demonstrated a significant economic burden associated with IBS-D in a US population, however they did not estimate out of pocket medical expenses in this population. These estimates could also vary widely given a patients insurance coverage, even if only considering the range of coverage for the recommended medications the survey participants noted. Together, these descriptions describe PI-IBS as a condition with significant economic and societal burden for which improved diagnostics, preventive strategies and effective treatments are sorely needed.
While no physicians initially prescribed antidepressant medication, 9% of the medications listed are nerve pain medication or antidepressants, SSRIs, or SNRIs. The American College of Gastroenterology recommends tricyclic anti-depressants (TCAs) for overall symptom improvement in IBS patients with a strong recommendation and high quality of evidence [11]. In addition, SSRIs are recommended for overall symptom improvement in IBS patients though with a weak recommendation, and low quality of evidence. TCAs and SSRIs have effects on central pain and psychological distress and may also impact bowel function by improving diarrhea by slowing GI transit (TCAs), and ameliorating constipation by accelerating GI transit (SSRIs) [17, 18].
While we did not ask physicians if they were aware of any current risk scores for PI-IBS [19] or how using a risk score would change their current practice, the finding that the majority of physicians would use a risk score if available is promising. However previous studies have shown that PCPs are not aware of these tools and do not use them [6, 7]. This is understandable, given there is only one risk score currently published [19], and only one study that has used the score in a different patient population [20]. Future research in this area should focus on how existing or newly developed risk scores change current practice, diagnostic strategies, or patient outcomes for treatment of PI-IBS.
Strengths & Limitations
This survey contributes to the literature about treatment and management of PI-IBS as no previous literature has focused on physician knowledge and treatment of PI-IBS. The small sample size is a noted limitation which likely affects the precision and generalizability of the estimates we described. Additionally we did not include nurse practitioners or physician assistants which are often “frontline” providers for treatment of IBS. Finally, after reviewing the wording of some of the questions in the survey, it is possible that some physicians responded to the questions given how they “should” approach a treatment or diagnostic step rather than what they actually do in their practice.
