Original article S276 Journal of Research in Medical Sciences | March 2012 Special Issue (2) | Irritable bowel syndrome–like symptoms in patients with inflammatory bowel disease in clinical remission phase are related to gut inflammation Hamid Tavakkoli 1 , Maryam Haghdani 2 , Saeid Haghdani 3 , Monireh Tavakkoli 4 , Hamed Daghaghzadeh 5 , Ali Gholamrezaei 6 , Peyman Adibi 7 1 Associate Professor, Integrative Functional Gastroenterology Center And Department of Gastroenterology, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran. 2 Resident of Internal Medicine, Department of Gastroenterology, Alzahra University Hospital And Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran. 3 Resident, Department of Urology, Tehran University of Medical Sciences, Tehran, Iran. 4 Research Assistant, Integrative Functional Gastroenterology Center, Isfahan University of Medical Sciences, Isfahan, Iran. 5 Assistant Professor, Integrative Functional Gastroenterology Center And Department of Gastroenterology, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran. 6 Research Assistant, Poursina Hakim Research Institute, Isfahan, Iran, 7 Professor, Integrative Functional Gastroenterology Center And Department of Gastroenterology, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran. BACKGROUND: Symptoms consistent with irritable bowel syndrome (IBS) are common among patients with inflammatory bowel disease (IBD) in remission phase, and clinicians have difficulties in interpreting such symptoms as an ongoing disease activity or a coexistent IBS. We investigated if the assessment of fecal calprotectin (FC) could be helpful in this regard. METHODS: The study population consisted of 42 IBD patients in remission that fulfilled the IBS diagnostic criteria (Rome III), 24 IBS patients and 30 healthy controls. Clinical remission was determined based on physician’s assessments, not using corticosteroids or biological agents within the preceding six months and activity indices. The FC and C-reactive protein (CRP) levels were investigated and compared among the groups. RESULTS: FC levels were significantly higher in patients with IBD (142.9 ± 216.5 μg/g) than those with IBS (24.9 ± 27.8 μg/g) and controls (17.9 ± 14.8 μg/g) (p < 0.001). CRP levels were also higher in IBD than IBS patients [3.9 (SE = 0.5) vs. 2.1 (SE = 0.5), p = 0.030]. However, FC levels were not significantly correlated with CRP levels or with severity of symptoms in IBD and IBS patients (p > 0.05). CONCLUSIONS: The presence of IBS-like symptoms in IBD patients in clinical remission may reflect an ongoing activity of IBD, which is undetectable by current activity indices. Serum CRP levels are not specific enough in such situation, and FC is a more accurate and specific test for investigating mucosal inflammation in this regard. KEYWORDS: Inflammatory Bowel Disease, Crohn’s Disease, Ulcerative Colitis, Remission, Inflammation, Irritable Bowel Syndrome BACKGROUND There is a considerable overlap between symptoms of irritable bowel syndrome (IBS) and those of the inflammatory bowel diseases (IBD). [1] Some studies showed that in patients with IBD in the remission phase, IBS‐like symptoms are present in more than 30% of the cases, two to three times higher than that in the general population. [2,3] On the other hand, there is evidence related to the possible role of mi‐ croscopic inflammation and mucosal immune sys‐ tem activation in IBS patients, especially those with diarrhea‐predominant subtype. [4,5] Considering the high prevalence of IBS (up to 25% to 50% of refer‐ rals to gastroenterology clinics) [6] and the role of mucosal immunity changes in the pathophysiology of IBS, clinicians are frequently challenged whether in an IBD patient in remission phase the presence of IBS‐like symptoms is indicative of an actual IBS or reflects the ongoing activity of IBD. The optimal therapeutic target to modify the disease course in IBD patients should be the full mucosa healing, and not only the clinical remission. [7,8] Therefore, accu‐ rate evaluation of the etiology of symptoms and diagnosing low‐grade inflammation in IBD patients in remission phase is important to optimize and individualize the treatment. [7,9] Conventional clinical activity indices, such as Crohn’s Disease Activity Index (CDAI) and Colitis Activity Index (CAI) and also traditional laboratory markers of inflammation, such as C‐reactive protein (CRP), lack the sensitivity and specificity to detect low‐grade inflammation in IBD patients. Therefore, these indices and laboratory markers do not help the clinician to distinguish subclinical IBD with low‐grade inflammation from coexisting IBS. [10‐12] Fecal calprotectin (FC), a recently investigated bio‐ marker of mucosal inflammation, is a calcium‐ binding protein found in neutrophils which is de‐ tectable in stool after mucosal inflammation and damage. [13,14] FC is highly correlated with clinical scores, serological markers, and more importantly with histologic grading of mucosal inflamma‐ tion. [15,16] As neutrophils are not involved in Address for correspondence: Hamid Tavakkoli, Associate Professor, Integrative Functional Gastroenterology Center And Department of Gastroenterol- ogy, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran. E-mail: h_tavakkoli@med.mui.ac.ir Received: 25.12.2011; Revised: 23.01.2012; Accepted: 18.02.2012 www.mui.ac.ir