Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society
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Neurogastroenterol. Motil. · Nov 2014
Randomized Controlled TrialSacral nerve stimulation changes rectal sensitivity and biomechanical properties in patients with irritable bowel syndrome.
Sacral nerve stimulation (SNS) has been demonstrated to alleviate symptoms and improve quality of life in selected patients with irritable bowel syndrome (IBS). The mechanisms of action, however, remain unknown. The aim of the study was to evaluate the effects of SNS on rectal sensitivity and biomechanical properties in patients with IBS. ⋯ SNS for diarrhea-predominant and mixed IBS relaxes the rectal wall, while making it more sensitive to stretch and less sensitive to cold. Reduced wall stiffness and increased sensitivity to stretch are associated with improved GSRS-IBS symptom score.
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Neurogastroenterol. Motil. · Oct 2014
Randomized Controlled TrialInfluence of repeated infusion of capsaicin-contained red pepper sauce on esophageal secondary peristalsis in humans.
The transient receptor potential vanilloid 1 has been implicated as a target mediator for heartburn perception and modulation of esophageal secondary peristalsis. Our aim was to determine the effect of repeated esophageal infusion of capsaicin-contained red pepper sauce on heartburn perception and secondary peristalsis in healthy adults. ⋯ Repeated esophageal infusion of capsaicin appears to attenuate heartburn perception and inhibit distension-induced secondary peristalsis in healthy adults. These results suggest capsaicin-sensitive afferents in modulating sensorimotor function of secondary peristalsis in human esophagus.
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Neurogastroenterol. Motil. · Oct 2014
ReviewEmerging treatments in neurogastroenterology: a multidisciplinary working group consensus statement on opioid-induced constipation.
Opioids are effective for acute and chronic pain conditions, but their use is associated with often difficult-to-manage constipation and other gastrointestinal (GI) effects due to effects on peripheral μ-opioid receptors in the gut. The mechanism of opioid-induced constipation (OIC) differs from that of functional constipation (FC), and OIC may not respond as well to most first-line treatments for FC. The impact of OIC on quality of life (QoL) induces some patients to decrease or stop their opioid therapy to relieve or avoid constipation. ⋯ At a roundtable meeting on OIC, a working group developed a consensus definition for OIC diagnosis across disciplines and reviewed current OIC treatments and the potential of treatments in development. By consensus, OIC is defined as follows: 'A change when initiating opioid therapy from baseline bowel habits that is characterized by any of the following: reduced bowel movement frequency, development or worsening of straining to pass bowel movements, a sense of incomplete rectal evacuation, or harder stool consistency'. The working group noted the prior validation of a patient response outcome and end point for clinical trials and recommended future efforts to create treatment guidelines and QoL measures specific for OIC. Details from the working group's discussion and consensus recommendations for patient care and research are presented in this article.
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Neurogastroenterol. Motil. · Oct 2014
ReviewSite and mechanism of morphine tolerance in the gastrointestinal tract.
Opioid-induced constipation is a major clinical problem. The effects of morphine, and other narcotics, on the gastrointestinal tract persist over long-term use thus limiting the clinical benefit of these excellent pain relievers. The effects of opioids in the gut, including morphine, are largely mediated by the μ-opioid receptors at the soma and nerve terminals of enteric neurons. ⋯ Here, we review the mechanisms by which tolerance develops in the small but not the large intestine. The regional differences lie in the signaling and regulation of the μ-opioid receptor in the various segments of the gastrointestinal tract. The differential role of β-arrestin2 in tolerance development between central and enteric neurons defines the potential for therapeutic approaches in developing ligands with analgesic properties and minimal constipating effects.
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Neurogastroenterol. Motil. · Oct 2014
Quantification of in vivo colonic motor patterns in healthy humans before and after a meal revealed by high-resolution fiber-optic manometry.
Until recently, investigations of the normal patterns of motility of the healthy human colon have been limited by the resolution of in vivo recording techniques. ⋯ This work provides the first comprehensive description of colonic motor patterns recorded by high-resolution manometry and demonstrates an abundance of retrograde propagating motor patterns. The propagating motor patterns appear to be generated by two independent sources, potentially indicating their neurogenic or myogenic origin.