Authors: Bouin M, Lupien F, Riberdy M, Boivin M, Plourde V, Poitras P.

Institution: Gastroenterology unit, Hopital Saint-Luc, Universite de Montreal, Montreal, Quebec, Canada.

Summary: Functional gastrointestinal disorders (FGID) are characterized by visceral hypersensitivity that could be specific to a region of the gut or reflect a diffuse pan-intestinal disorder.

Sensory thresholds to distension at two visceral sites in patients with different FGIDs were determined. According to Rome II criteria, 30 patients from three groups were studied: patients with (i) functional dyspepsia (FD) or (ii) irritable bowel syndrome (IBS), and (iii) patients with concomitant symptoms of FD and IBS. Pain thresholds to balloon distension were determined in stomach and rectum.

In FD patients, gastric intolerance to balloon distension was found in 91% patients; rectal hypersensitivity was documented in 18% patients. In IBS patients, rectal hypersensitivity was seen in 75% patients; while gastric hypersensitivity was never found. In patients with concomitant symptoms of FD + IBS, gastric and rectal intolerance to distension were present respectively in 82 and 91% patients.

In the whole group, visceral intolerance to distension was documented at one site in 90% patients and at both sites, i.e. stomach and rectum, in 33% patients. Visceral intolerance to distension can be pan-intestinal in patients with multiple sites of symptoms, but appears organ-specific in patients exhibiting a specific site of symptoms.

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15198653&query_hl=3

Authors: Pimentel M, Rossi F, Chow EJ, Ofman J, Fullerton S, Hassard P, Lin HC.

Institution: GI Motility Program, Department of Medicine, Cedars-Sinai Medical Center, CSMC Burns & Allen Research Institute, Los Angeles, California 90048, USA. mark.pimentel@cshs.org

Aims: To determine the prevalence of irritable bowel syndrome (IBS) in subjects with gastroesophageal reflux disease (GERD) compared with non-GERD controls.

Method: Two hundred subjects were identified from a list of Cedars-Sinai Medical Foundation patients and gastroenterology motility practice subjects with and without a potential diagnosis of GERD. All subjects were then evaluated independently by two blinded physicians who were asked to identify subjects with GERD based on taking a history (gold standard). A follow-up questionnaire was later mailed to patients. This questionnaire included Rome I criteria for IBS. The prevalence of IBS was compared between GERD and non-GERD subjects. Finally, to further strengthen the method, a retrospective review of all subjects' charts was conducted to identify patients who had had 24-hour pH tests, and the prevalence of IBS was determined in this subgroup.

Results: Of the 200 subjects, 90 (45%) patients returned the questionnaire. After excluding subjects with IBD and incomplete questionnaires, there were 84 subjects (35 with GERD) included in the analysis. Of the 35 GERD subjects, 25 (71%) were Rome I criteria positive for IBS, whereas only 17 of the 49 (35%) non-GERD subjects had IBS (odds ratio = 54.7, CI = 1.7-13.5, p < 0.01). In 11 of the GERD subjects a 24-hour pH study was available and confirmed GERD. Of these 11 subjects, 7 (64%) met Rome I criteria for IBS.

Conclusion: There is a higher prevalence of IBS in subjects with GERD compared with subjects without GERD.

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11873099&query_hl=145

Authors: Wang JH, Luo JY, Dong L, Gong J, Tong M.

Institution: Department of Gastroenterology, Second Hospital of Xi'an Jiaotong University, Xi'an 710004, Shaanxi Province, China. jinhaiwang@hotmail.com

Aims: Gastroesophageal reflux disease (GERD) is a common disorder in the Western population, but detailed population-based data in China are limited. The aim of this study was to understand the epidemiology of symptomatic gastroesophageal reflux (SGER) in adults of Xi'an, a northwestern city of China, and to explore the potential risk factors of GERD.

Methods: Symptoms suggestive of GERD, functional dyspepsia (FD), irritable bowel syndrome (IBS), upper respiratory diseases and some potential risk factors were investigated in a face-to-face manner in a region-stratified random samples of 2789 residents aged 18-70 years in Xi'an by using a standardized questionnaire.

Conclusion: GERD is common in Xi'an's adult population with a mild or moderate degree. The etiology and pathogenesis of GERD are probably associated with FD, IBS, and some respiratory, laryngopharyngeal and odontostological diseases or symptoms. Some lifestyles, diseases and dietary factors are the risk factors of GERD.

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15162542&dopt=Citation

Authors: Corsetti M, Caenepeel P, Fischler B, Janssens J, Tack J.

Institution: Department of Internal Medicine, Division of Gastroenterology, University Hospital Gasthuisberg, University of Leuven, Leuven, Belgium.

Aim: Epidemiological studies suggest considerable overlap between functional dyspepsia (FD) and irritable bowel syndrome (IBS). The aim of the present study was to investigate whether coexisting IBS is also associated with symptom pattern or pathophysiology in FD. ntion and accommodation to a meal, and gastric emptying breath test.

Results: Fifty-four percent of the patients had FD alone, whereas 46% had FD + IBS. FD + IBS patients were more likely to be female (75%vs 60%, p < 0.01) and to have a greater weight loss (5.4 +/- 0.6 vs 3.5 +/- 0.4 kg, p < 0.05). Coexisting IBS did not increase the risk of having any of the dyspeptic symptoms but the overall symptom severity was significantly higher in FD + IBS (12.4 +/- 0.4 vs 9.8 +/- 0.3, p < 0.01). FD + IBS patients had a lower threshold for first perception (2.9 +/- 0.3 vs 3.8 +/- 0.3 mmHg, p < 0.05) and for discomfort (7.9 +/- 0.4 vs 9.5 +/- 0.5 mmHg, p < 0.05) and a greater prevalence of hypersensitivity to gastric distention (44%vs 28%, p < 0.05). Gastric emptying, accommodation to a meal, and prevalence of H. pylori infection did not differ in the two groups.

Conclusion: About half of the FD patients fulfill the Rome II criteria for IBS. FD + IBS is more prevalent in female patients and is associated with a higher weight loss, with greater overall symptom severity, and with hypersensitivity to distention.

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15180740&query_hl=87

Authors: Talley NJ, Dennis EH, Schettler-Duncan VA, Lacy BE, Olden KW, Crowell MD.

Institution: Mayo Foundation, Mayo Medical School, Rochester, Minnesota 55905, USA.

Objectives: Distinguishing between irritable bowel syndrome (IBS) and functional dyspepsia can be challenging because of the variations in symptom patterns, which commonly overlap. However, the overlap is poorly quantified, and it is equally uncertain whether symptom patterns differ in subgroups of IBS arbitrarily defined by primary bowel patterns of constipation (IBS-C) and diarrhea (IBS-D). We aimed to determine and to compare the distribution of GI symptoms, both, upper and lower, among IBS-C and IBS-D patients.

Results: IBS-C patients reported significantly more overall GI symptoms when compared to patients with IBS-D (6.67 vs 4.62, respectively, p<0.001). Abdominal pain patterns differed in patients with IBS-C versus IBS-D (lower abdominal pain: 40.8% vs 24.4% p=0.05 and upper abdominal pain: 36.8% vs 24.4%, respectively). Bloating was substantially more common in IBS-C patients (75%) than in IBS-D (40.9%). There were no significant differences in personality subscales by IBS subgroup; however, somatization was positively associated with multiple symptom reports and was negatively correlated with quality of life.

Conclusions: Upper GI symptoms consistent with functional dyspepsia were more frequent in IBS-C. Although there was considerable overlap of upper and lower GI symptoms in patients with IBS-C and IBS-D, the former had more frequent lower abdominal pain and bloating.

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14638348&query_hl=84

Authors: Holtmann G, Goebell H, Talley NJ.

Institution: Division of Gastroenterology, University of Essen, Germany.

Objectives: Alterations of mechanosensitive thresholds occur in a subset of patients with functional dyspepsia and irritable bowel syndrome (IBS). However, symptoms associated with these two conditions frequently overlap. It is not known how often subjects with and without symptom overlap have abnormal intestinal sensory thresholds. Our objective was to assess the pattern of symptoms and small intestinal sensory thresholds in patients with functional disorders.

Methods: We studied 157 consecutive patients who had undergone extensive diagnostic work-up to exclude organic disease. Abdominal symptoms were assessed with a validated instrument, and patients were categorized as having functional dyspepsia, IBS, or both. With a barostat device, we tested small intestinal mechanosensitive function in 22 randomly selected patients from this population (with functional dyspepsia, IBS, or both) and 22 healthy controls.

Conclusions: Small intestinal mechanosensitive pathways are disturbed in patients with functional dyspepsia and IBS. Differences in the pattern and localization of symptoms probably do not reflect differences in small intestinal sensory thresholds. Functional dyspepsia and IBS cannot be distinguished on the basis of altered small intestinal sensory thresholds.

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9177509&dopt=Citation

Authors: F. Cremonini and N. J. Talley

Institution: Clinical Enteric Neuroscience Translational and Epidemiological Research (C.E.N.T.E.R.) Program, Mayo Clinic, Rochester, MN, USA

Summary:Functional dyspepsia and irritable bowel syndrome are currently considered to be two separate nosological entities. However, the overlap of symptoms and the evidence of a number of common pathophysiological characteristics suggest that functional dyspepsia and irritable bowel syndrome may be different presentations of the same disorder.

In this review, we critically appraise points in common, as well as differences, in the epidemiology, pathophysiology and response to treatment of functional dyspepsia and irritable bowel syndrome. Population-based studies and large case series show that one- to two-thirds of subjects with irritable bowel syndrome have symptoms that overlap with functional dyspepsia.

Symptom analyses have generally failed to support functional dyspepsia and irritable bowel syndrome as separate entities. An exaggerated motor response to meals, delayed gastric emptying and abnormal small bowel and colonic transit can all be found in subsets of functional dyspepsia and irritable bowel syndrome, and are not exclusive to either condition.

Visceral hypersensitivity is a common feature to both entities and seems unlikely to be site or disease specific. There is good evidence for the post-infectious development of irritable bowel syndrome, and this may also apply in functional dyspepsia.

Study link: http://www.blackwell-synergy.com/links/doi/10.1111%2Fj.1365-2036.2004.02184.x