Journal of Neurogastroenterology and Motility 2016; 22(4): 545-546  https://doi.org/10.5056/jnm16157
Irritable Inflammatory Bowel Syndrome as a Distinct Disease Entity
Jung Hwan Oh
Division of Gastroenterology, Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
Correspondence to: Jung Hwan Oh, MD, Department of Internal Medicine, St. Paul’s Hospital, College of Medicine, The Catholic University of Korea, 180, Wangsan-ro, Dongdaemun-gu, Seoul 02559, Korea, Tel: +82-2-958-2114, Fax: +82-2-968-7250, E-mail: ojh@catholic.ac.kr
Received: September 20, 2016; Accepted: September 20, 2016; Published online: October 1, 2016.
© The Korean Society of Neurogastroenterology and Motility. All rights reserved.

cc This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Body

The prevalence of inflammatory bowel disease (IBD) is increasing in Asia.1 Although IBD is known to be a rare disease, irritable bowel syndrome (IBS) is a common condition in the general population. Six percent of the Korean population seeks medical treatment for IBS at least once a year.2 Even though IBD and IBS seem to be independent entities, they have similar pathogeneses such as mucosal inflammation, intestinal permeability, and dysbiosis.3 It was suggested that IBS and IBD represent a part of the same disease spectrum.4

When IBD patients have lower gastrointestinal symptoms, the clinician would be in a predicament regarding further management, since it augments the possibility of either a remaining active inflammation, or a coexisting IBS symptom development that is a remission of IBD. The concept of irritable inflammatory bowel syndrome (IIBS) has been suggested.5 The diagnostic criteria for IIBS is as follows. First, patients should have IBD and be in a clinical remission state with normal C-reactive protein, and Crohn’s disease (CD) activity index < 150, or its equivalent derived from other disease activity indices. Second, the Rome III criteria should be fulfilled for a diagnosis of IBS.

In this issue of the Journal of Neurogastroenterology and Motility, Tomita et al6 report on the prevalence IBS-like symptoms in inactive IBD patients. In this regard, this research applied to IIBS. They concluded that the prevalence of IBS-like symptoms in inactive IBD patients was higher than in healthy controls. The prevalence of IBS-like symptoms in inactive ulcerative colitis (UC) was 17.5% and inactive CD was 27.1% compared to 5.3% of healthy controls. Interestingly, the prevalence of IBS-like symptoms in IBD patients was lower compared to previous studies, because they defined IBD and IBS clearly. That is, inactive IBD was defined based on the clinical disease activity index and C-reactive protein measurements, which are readily used in clinics, while IBS was defined according to the Rome III criteria. The above are compatible with the diagnostic criteria of IIBS. Is there any useful tool which can diagnose this new disease entity? Fecal calprotectin is probably a good answer. Calprotectin levels were elevated in IBD patients in the remission stage,7 in comparison with normal range in IBS patients. Measuring fecal calprotectin would be a useful step to differentiate active IBD and overlapping IBS symptoms in IBD patients.4

CD patients showed low quality of life and higher anxiety scores in this study. Patients with IBD in remission who suffer IBS-like symptoms experienced fatigue, and disease-related worries.8 Bidirectional communications between the gut microbiota, gut permeability, and the central nervous system exist. Increased gut permeability which is an important pathologic process in IBD and IBS seems to be the keystone of the microbiome-gut-brain interaction.9 Antidepressants may be a possible management of IBS-like symptoms in IBD patients. Amitriptyline and selective serotonin-reuptake inhibitors are effective for treating psychological symptoms in IBD patients.10 The evidence of probiotic therapy for IBS is still poor because of insufficient efficacy of current data,11 and therefore, probiotic therapy for IIBS is still questionable.

This was a retrospective cross sectional study, therefore, it would not be expected if initial disease severity correlated with development of IBS-like symptoms during clinical course. The prevalence of IBS-like symptoms in the CD group was higher than that of the UC group in this study, which corresponds to previous studies. It may be related to small intestine involvement in CD patients. However, patients who underwent surgery were found only in the CD group in this study, where more IBS-like symptoms would occur associated with ileus than UC patients without having a past surgical history.

In summary, it is difficult in IBD patients to discern between active IBD and coexisting IBS symptoms in the remission state. The pathogenesis of IBS in IBD patients is incompletely understood compared to that of IBS in the healthy population. However, IBS-like symptoms in IBD patients should be focused on as a new distinct disease entity. The authors’ work raised the importance of IBS-like symptoms in IBD patients. Many more researches in this field are expected from now on.

References
  1. Ng, WK, Wong, SH, and Ng, SC (2016). Changing epidemiological trends of inflammatory bowel disease in Asia. Intest Res. 14, 111-119.
    Pubmed KoreaMed CrossRef
  2. Jung, HK, Kim, YH, and Park, JY (2014). Estimating the burden of irritable bowel syndrome: analysis of a nationwide korean database. J Neurogastroenterol Motil. 20, 242-252.
    Pubmed KoreaMed CrossRef
  3. Gracie, DJ, and Ford, AC (2015). IBS-like symptoms in patients with ulcerative colitis. Clin Exp Gastroenterol. 8, 101-109.
    Pubmed KoreaMed CrossRef
  4. Quigley, EM (2016). Overlapping irritable bowel syndrome and inflammatory bowel disease: less to this than meets the eye?. Therap Adv in Gastroenterol. 9, 199-212.
    CrossRef
  5. Stanisic, V, and Quigley, EM (2014). The overlap between IBS and IBD: what is it and what does it mean?. Expert Rev Gastroenterol Hepatol. 8, 139-145.
    Pubmed CrossRef
  6. Tomita, T, Kato, Y, and Takimoto, M (2016). Prevalence of irritable bowel syndrome?like symptoms in Japanese patients with inactive inflammatory bowel disease. J Neurogastroenterol Motil. 22, 661-669.
    Pubmed CrossRef
  7. Jelsness-Jørgensen, LP, Bernklev, T, and Moum, B (2013). Calprotectin is a useful tool in distinguishing coexisting irritable bowel-like symptoms from that of occult inflammation among inflammatory bowel disease patients in remission. Gastroenterol Res Pract. 2013, 620707.
    Pubmed KoreaMed CrossRef
  8. Jelsness-Jørgensen, LP, Bernklev, T, and Moum, B (2012). Fatigue and disease-related worries among inflammatory bowel disease patients in remission; is it a reflection of coexisting IBS-like symptoms? A short report. J Psychosom Res. 73, 469-472.
    Pubmed CrossRef
  9. Yarandi, SS, Peterson, DA, Treisman, GJ, Moran, TH, and Pasricha, PJ (2016). Modulatory effects of gut microbiota on the central nervous system: how gut could play a role in neuropsychiatric health and diseases. J Neurogastroenterol Motil. 22, 201-212.
    Pubmed KoreaMed CrossRef
  10. Abraham, BP (2015). Symptom management in inflammatory bowel disease. Expert Rev Gastroenterol Hepatol. 9, 953-967.
    Pubmed CrossRef
  11. Mazurak, N, Broelz, E, Storr, M, and Enck, P (2015). Probiotic therapy of the irritable bowel syndrome: why is the evidence still poor and what can be done about it?. J Neurogastroenterol Motil. 21, 471-485.
    Pubmed KoreaMed CrossRef


This Article

e-submission

Archives

Aims and Scope