Abstract and Introduction
Background: The long-term natural history and impact of irritable bowel syndrome (IBS)-type symptoms on outcomes in inflammatory bowel disease (IBD) are uncertain.
Aim: To assess this in a longitudinal follow-up study of patients in secondary care
Methods: We assessed the natural history of IBS-type symptoms in IBD via Rome III criteria applied at baseline, and 2 and 6 years. We defined longitudinal disease activity as the need for glucocorticosteroids or flare, escalation, hospitalisation or intestinal resection. To assess healthcare utilisation, we recorded the number of outpatient clinic attendances and investigations. We also collected anxiety, depression and somatoform symptom scores and quality of life scores during follow-up.
Results: Among 125 individuals with Rome III data at all three time points, only 41 (32.8%) never reported IBS-type symptoms. Fifteen patients (12.0%) had IBS-type symptoms at baseline that resolved, 19 (15.2%) had fluctuating symptoms, 35 (28.0%) had new-onset symptoms, and 15 (12.0%) had persistent symptoms. Among more than 300 patients with IBD activity data, IBS-type symptoms were not associated with an increased likelihood of the need for glucocorticosteroids or flare, escalation, hospitalisation or intestinal resection. However, the mean numbers of outpatient appointments and endoscopic investigations were significantly higher among those with IBS-type symptoms. Anxiety, depression and somatoform symptom scores were significantly higher, and quality of life scores were significantly lower, in those reporting IBS-type symptoms at least once during the study.
Conclusions: IBS-type symptoms affected more than two-thirds of patients with IBD during >6 years of follow-up and were associated with increased healthcare utilisation, and worse anxiety, depression, somatoform symptom and quality of life scores, but not adverse disease activity outcomes.
Inflammatory bowel disease (IBD), which encompasses Crohn's disease (CD) and ulcerative colitis (UC), is a chronic gastrointestinal disorder with an increasing prevalence globally. It is estimated that by 2028, due to the fact that incidence exceeds mortality, 1% of the population in some Western countries will have IBD. There is no cure for either CD or UC, and patients experience recurrent flares of disease activity with diarrhoea, rectal bleeding and abdominal pain. Symptoms during flares of activity may overlap with those of irritable bowel syndrome (IBS), a disorder of gut–brain interaction characterised by abdominal pain and altered stool frequency or form. IBS is more common than IBD, affecting between 5% and 10% of the general population. However, the prevalence of symptoms compatible with IBS in patients with IBD is up to three times higher than in the general population,[4,5] and such symptoms impact negatively on psychological health and quality of life.
Although some investigators have suggested that IBS-type symptoms are a manifestation of disease activity, their presence does not necessarily correlate with inflammation. Even among patients with IBD in deep endoscopic and/or histological remission up to 25% report symptoms consistent with IBS. The aetiology of both IBS and IBD is uncertain. However, abnormal intestinal permeability, perturbations of the intestinal microbiota, immune activation and mucosal inflammation are common to both.[10–12] Given that IBS is highly prevalent, the co-existence of IBS-type symptoms in IBD may occur by chance, but IBS can also be precipitated by acute gastrointestinal inflammation, the best-known examples being after acute enteric infection or diverticulitis.[13,14] Given this, IBD may itself be a risk factor for developing IBS.
Confusion between IBS-type symptoms and ongoing IBD activity can lead to difficulties in making clinical decisions about treatment based on symptoms alone. In addition, there are concerns that such symptoms are a manifestation of disease activity and may, therefore, impact adversely on prognosis. Despite this, there have been few studies examining this issue. One relatively small Swedish study of 94 patients with UC in endoscopic remission reported that the presence of these symptoms at baseline was not associated with subsequent disease activity. A previous study from our group did not demonstrate any adverse impact of IBS-type symptoms on objective measures of subsequent disease activity in patients with IBD in biochemical remission at baseline. However, the follow-up in these two studies was limited to 1 year and 2 years, respectively, and there may have been insufficient time for some of the rarer endpoints, such as hospitalisation or intestinal resection, to occur.
A recent expert review has highlighted the need for a better understanding of the course of IBS-type symptoms in IBD as well as their impact on prognosis. We, therefore, conducted a further follow-up of individuals in our previous study 6 years after recruitment. We hypothesised that these symptoms would not be associated with adverse disease outcomes but would lead to increased healthcare utilisation and, if persistent, have a greater impact on psychological health and quality of life.
Aliment Pharmacol Ther. 2022;56(8):1264-1273. © 2022 Blackwell Publishing