Inter-observer agreement for diagnostic classification of esophageal motility disorders defined in high-resolution manometry.

High-resolution esophageal manometry (HRM) is a recent development used in the evaluation of esophageal function. Our aim was to assess the inter-observer agreement for diagnosis of esophageal motility disorders using this technology. Practitioners registered on the HRM Working Group website were invited to review and classify (i) 147 individual water swallows and (ii) 40 diagnostic studies comprising 10 swallows using a drop-down menu that followed the Chicago Classification system. Data were presented using a standardized format with pressure contours without a summary of HRM metrics. The sequence of swallows was fixed for each user but randomized between users to avoid sequence bias. Participants were blinded to other entries. (i) Individual swallows were assessed by 18 practitioners (13 institutions). Consensus agreement (≤ 2/18 dissenters) was present for most cases of normal peristalsis and achalasia but not for cases of peristaltic dysmotility. (ii) Diagnostic studies were assessed by 36 practitioners (28 institutions). Overall inter-observer agreement was 'moderate' (kappa 0.51) being 'substantial' (kappa > 0.7) for achalasia type I/II and no lower than 'fair-moderate' (kappa >0.34) for any diagnosis. Overall agreement was somewhat higher among those that had performed >400 studies (n = 9; kappa 0.55) and 'substantial' among experts involved in development of the Chicago Classification system (n = 4; kappa 0.66). This prospective, randomized, and blinded study reports an acceptable level of inter-observer agreement for HRM diagnoses across the full spectrum of esophageal motility disorders for a large group of clinicians working in a range of medical institutions. Suboptimal agreement for diagnosis of peristaltic motility disorders highlights contribution of objective HRM metrics.

Association of enteroaggregative Escherichia coli with irritable bowel syndrome.

Increased numbers of faecal Enterobacteriaceae are observed among patients with irritable bowel syndrome. Escherichia coli strains are present in the lower intestine of humans, and may include several potentially pathogenic adhesive pathotypes. The aim of this study was to determine whether there were differences between the adhesive pathotypes of E. coli strains recovered from stool specimens of patients with irritable bowel syndrome and those recovered from healthy controls. The ability of E. coli isolates to adhere to cultured epithelial cells was assessed in an in-vitro adherence assay with HEp-2 cells. Enteroaggregative E. coli (EAEC) strains were isolated significantly more frequently (p <0.00001) from patients with irritable bowel syndrome (81.8%) than from healthy controls (32.3%). However, despite this association, the precise role of the EAEC pathotype in irritable bowel syndrome remains to be determined.

Diagnostic difficulties during combined multichannel intraluminal impedance and pH monitoring in patients with esophagitis or Barrett's esophagus.

Gastroesophageal reflux disease (GERD) is one of the most common esophageal diseases in developed countries. It is widely believed that GERD symptoms are caused by acid refluxate within the esophagus, so ambulatory 24 hour pH-monitoring became the gold standard in detecting gastroesophageal reflux. Traditional ambulatory pH monitoring is unable to detect a gastroesophageal reflux with pH >4. The introduction of multichannel intraluminal impedance and pH (MII-pH) brought new possibilities in detecting GERD. In this technique impedance identifies reflux episode whereas pH sensor further characterizes it as either acid (pH <4) or non-acid (pH > or =4). This is a great progress in diagnosing GERD but MII has also some imperfections related to pathological changes in the esophageal mucosa such as esophagitis or Barrett oesophagus, which are connecting with a very low baseline impedance values. Changes in the esophageal mucosa may also impair the esophageal motility and esophageal transit leading to some fluid retention in the esophagus. It should be stressed that very low impedance baseline creates a difficulty in interpreting the MII-pH study. In such a case it might be almost impossible to interpret the study as the interpreter does not see characteristic drop in impedance progressing either orally (reflux episode) or swallow but only almost flat impedance lines. Therefore, future studies are needed to further evaluate this problem.