Opioid-induced bowel dysfunction: epidemiology, pathophysiology, diagnosis, and initial therapeutic approach.

Opioids affect motor and sensory function throughout the gastrointestinal tract, and are frequently associated with a number of gastrointestinal symptoms including constipation, which impairs the quality of life and may limit the dose of opioid or result in discontinuation altogether. Patients with opioid-induced constipation should be assessed by careful history and physical examination, and in some cases where the diagnosis is unclear with select diagnostic tests. Few clinical studies have been conducted to assess the efficacy of various treatments.

IBS with constipation, functional constipation, painful and non-painful constipation: e Pluribus…Plures?

IBS with constipation (IBS-C) and chronic constipation (CC) can be difficult to distinguish clinically. The Rome III criteria create mutual exclusion between IBS-C and CC, based on the presence of abdominal pain, which is a defining criterion for IBS-C. Previous surveys found that up to 45% of CC patients have abdominal pain and other IBS features.

Effects of linaclotide in patients with irritable bowel syndrome with constipation or chronic constipation: a meta-analysis.

Background & Aims: Linaclotide is a minimally absorbed, 14-amino acid peptide used to treat patients with irritable bowel syndrome with constipation (IBS-C) or chronic constipation (CC). We performed a meta-analysis to determine the efficacy of linaclotide, compared with placebo, for patients with IBS-C or CC.

Methods: MEDLINE, EMBASE, and the Cochrane central register of controlled trials were searched for randomized, placebo-controlled trials examining the effect of linaclotide in adults with IBS-C or CC.

A critical appraisal of lubiprostone in the treatment of chronic constipation in the elderly.

Chronic constipation is a common disorder in the general population, with higher prevalence in the elderly, and is associated with worse quality of life and with greater health care utilization. Lubiprostone is an intestinal type-2 chloride channel activator that increases intestinal fluid secretion, small intestinal transit, and stool passage. Lubiprostone is currently approved by the US Food and Drug Administration for the treatment of chronic idiopathic constipation and of irritable bowel syndrome with predominant constipation.

Rifaximin for the treatment of irritable bowel syndrome.

Introduction: Few therapeutic options are available for irritable bowel syndrome (IBS). Lubiprostone is approved by the FDA for IBS with constipation, and alosetron in IBS with diarrhea (IBS-D). It has been proposed that alterations in the bowel microflora may play a role in the pathophysiology of IBS, and that modulation of the microflora holds therapeutic potential.

Obesity does not increase effects of synthetic ghrelin on human gastric motor functions.

Background & Aims: Ghrelin is secreted by the stomach and stimulates food intake. Obese individuals have lower fasting plasma ghrelin levels but increased appetite, suggesting greater responses to endogenous ghrelin in obesity. The aim of this study was to compare effects of exogenous ghrelin (at a dose that stimulates growth hormone [GH] release in the physiologic range) versus placebo on gastric emptying, gastric volume, and postprandial symptoms and determine whether body mass (ranging from normal weight to obesity) influences responses to ghrelin.

Levofloxacin-based triple therapy in first-line treatment for Helicobacter pylori eradication.

Background: The standard first-line therapies for Helicobacter pylori eradication are based on clarithromycin and amoxicillin or metronidazole. Recent studies suggested levofloxacin as an alternative option for both first-and second-line H. pylori eradication treatment.

Treatments targeting putative mechanisms in irritable bowel syndrome.

The pathophysiology of irritable bowel syndrome (IBS) is heterogeneous; it is possible for several mechanisms to be disturbed in the same patient. Isolating a single target for pharmacological manipulation is also difficult because of the complexity and overlap of the neural circuitry in the enteric and central nervous system. This review summarizes the rationale and efficacy of current and future therapies for IBS, on the basis of putative pathophysiological models.

Effect of gastric volume or emptying on meal-related symptoms after liquid nutrients in obesity: a pharmacologic study.

Background & Aims: Altered postprandial satiation influences food intake in obesity. The aim of this study was to evaluate the contribution of gastric motor functions to intra- and postprandial symptoms in obese, otherwise healthy, people.

Methods: In a randomized, parallel-group, double-blind design, 40 obese (body mass index>30 kg/m2) healthy volunteers (n=10/group) received intravenous saline (placebo), atropine (.

Effect of somatostatin analog on postprandial satiation in obesity.

Objective: Altered satiation may impact postprandial symptoms and potentially change food intake in obesity. Our aim was to compare effects of octreotide and placebo on postprandial symptoms, satiation, and gastric volumes in obesity.

Research Methods And Procedures: In a randomized, parallel-group, double-blind, placebo-controlled study, 26 obese but otherwise healthy participants received 100 mug of octreotide or placebo subcutaneously 30 minutes before each study.

Idiopathic chronic urticaria and celiac disease.

Idiopathic chronic urticaria (ICU) is a chronic relapsing cutaneous disease. Some case reports or studies on small series of celiac disease (CD) patients have suggested a possible association between CD and ICU. The aim of this study was to assess the prevalence of CD in a population of adults ICU patients with respect to healthy controls.

Frontiers in functional dyspepsia.

Functional dyspepsia (FD) refers to unexplained pain or discomfort in the upper abdomen and is commonly seen in gastroenterology practice. The underlying pathophysiologic mechanisms associated with FD are unclear, although traditionally, delayed gastric emptying, visceral hypersensitivity to acid or mechanical distention, and impaired gastric accommodation have been implicated as putative physiologic disturbances. It also remains uncertain whether FD and irritable bowel syndrome are different presentations of the same disorder.

Can 13C urea breath test predict resistance to therapy in Helicobacter pylori infection?

Background/aims: Results of 13C urea breath test (UBT), a noninvasive test for detecting active H. pylori infection, have been regarded also numerically for a possible predictive value on bacterial load and entity of mucosal inflammation. In the present study we wished to determine whether there is a particular value of Delta Over Baseline (DOB) result which could predict resistance to anti-H.

Diagnostic and therapeutic use of proton pump inhibitors in non-cardiac chest pain: a metaanalysis.

Objectives: To assess (i) the efficacy of short-term proton pump inhibitors (PPIs) in non-cardiac chest pain (NCCP) and (ii) the performance of an empirical short-term treatment with PPI (PPI test) to establish a diagnosis of abnormal acid reflux in NCCP.

Methods: Metaanalysis of English language studies identified by searching MEDLINE (1966-May 2004), EMBASE (1980-May 2004), Cochrane Controlled Trials Register, and abstract books from major gastroenterology meetings (1993-2004). For the metaanalysis of PPI efficacy in NCCP, we selected randomized controlled trials (parallel group and crossover designs) comparing PPI therapy with placebo.

Irritable bowel syndrome: epidemiology, natural history, health care seeking and emerging risk factors.

IBS is a common condition, affecting approximately 3% to 15% of the general population based on various diagnostic criteria. There seem to be differences in disease epidemiology between the eastern and the western world. As data from larger Asian epidemiological studies begin to surface,however, such differences appear to be less marked.

Effect of CCK-1 antagonist, dexloxiglumide, in female patients with irritable bowel syndrome: a pharmacodynamic and pharmacogenomic study.

Background: Cholecystokinin (CCK) is involved in gastrointestinal motor response to meals. The potential role of CCK receptor antagonists in functional gastrointestinal disorders is unclear.

Aims: To evaluate the effects of dexloxiglumide, a CCK-1 receptor antagonist, on gastrointestinal transit (GIT) and symptoms in patients with constipation-predominant IBS (C-IBS); and to explore the influence of CCK-1 receptor polymorphisms on gut transit and the pharmacodynamic response to therapy.

Contributions of gastric volumes and gastric emptying to meal size and postmeal symptoms in functional dyspepsia.

Background & Aims: The aim was to assess relative contributions of gastric volumes (GV) and gastric emptying (GE) to meal size and postprandial symptoms in patients with functional dyspepsia.

Methods: Patients with chronic upper gastrointestinal symptoms were prospectively evaluated. GV during fasting and after 300 mL Ensure was measured with 99m Tc-single-photon emission computed tomography imaging and solid GE (99m Tc-egg) by scintigraphy.

Direct visualization of intestinal villi by high-resolution magnifying upper endoscopy: a validation study.

Background: New generation videoendoscopes potentially may visualize duodenal villi. This study compared endoscopic findings with this type of instrument to the histopathologic evaluation of duodenal villi.

Methods: A total of 191 patients underwent upper endoscopy for the purpose of obtaining duodenal biopsy specimens.

Functional dyspepsia: drugs for new (and old) therapeutic targets.

The therapeutic management of functional dyspepsia remains a major challenge for the gastroenterologist. Current therapies available are based on putative underlying pathophysiologic mechanisms, including gastric acid sensitivity, slow gastric emptying and Helicobacter pylori infection, but only a small proportion of patients achieve symptomatic benefit from these therapeutic approaches. Relatively novel mechanistic concepts under testing include impaired gastric accomodation, visceral hypersensitivity, and central nervous system dysfunction.

The role of pelvic floor dysfunction and slow colonic transit in adolescents with refractory constipation.

Objective: Although pelvic floor dysfunction (PFD) is recognized as a cause of refractory constipation in adults, this diagnosis is not frequently considered in children and adolescents with refractory constipation. The purpose of this study was to examine the symptoms and colonic transit in adolescents with constipation evaluated for a disorder in pelvic floor function.

Methods: Adolescents with refractory constipation who had undergone anorectal manometry (ARM) and balloon expulsion test (BET) were identified by retrospective review of records.