ABSTRACT
BACKGROUND: In patients with functional dyspepsia (FD), tolerance to gastric fundus distension is frequently compromised. We tested the contribution of contractile cholinergic or relaxing nitrergic pathways in this disorder. METHODS: Thirty-nine patients (29 women, 10 men) with FD participated in this study. Gastric distension studies where carried out by inflating a fundic balloon until the maximum distension volume (MDV) tolerated by the patient. Gastric distension was first evaluated in basal control conditions before repeating the test after the injection of anticholinergic hyoscine (Buscopan 20 mg intravenous) or following the administration of nitric oxide donor nitroglycerin (Nitrolingual 1.2 mg sublingual). RESULTS: MDVs were significantly (P<0.01) lower in FD patients (495+/-27 ml) than in controls (995+/-59 ml). Intolerance to fundic distension was found in 77% of dyspepsia patients. Hyoscine improved the threshold for discomfort (343+/-21 versus 421+/-43 ml; P<0.05), as well as the MDV (510+/-36 versus 635+/-44 ml; P<0.01). This drug effect was seen in 71% (10/14) of patients. Nitroglycerin failed to modify thresholds. However, improved tolerance was seen in 15% (2/13) of the patients. CONCLUSION: Intolerance to fundic distension is a frequent finding in FD (77% patients). The cholinergic pathway seems to be a predominant factor involved in tolerance to distension in patients with FD. Fundus-relaxing drugs should be considered for the treatment of dyspepsia.
Subject(s)
Dyspepsia/physiopathology , Gastric Fundus/physiopathology , Muscarinic Antagonists/therapeutic use , Scopolamine/therapeutic use , Somatosensory Disorders/physiopathology , Adult , Aged , Cholinergic Fibers/physiology , Dyspepsia/complications , Dyspepsia/drug therapy , Enteric Nervous System/physiopathology , Female , Humans , Male , Middle Aged , Nitric Oxide Donors/therapeutic use , Nitroglycerin/therapeutic use , Sensory Thresholds/drug effects , Somatosensory Disorders/drug therapy , Somatosensory Disorders/etiology , Stress, Mechanical , Treatment OutcomeABSTRACT
BACKGROUND & AIMS: Visceral hypersensitivity was detected in patients with functional gastrointestinal disorders and has been proposed as a biological marker of irritable bowel syndrome (IBS). The purpose of this study was to assess the sensitivity, specificity, and the predictive values of pain thresholds evaluated by rectal distention using an electronic barostat in patients with or without IBS and in control subjects. METHODS: Patients were diagnosed according to Rome II criteria. Rectal sensory thresholds were determined in 164 patients (86 IBS patients, 26 painless constipation, 21 functional dyspepsia, and 31 miscellaneous conditions) and in 25 normal controls. All subjects underwent a series of rectal isobaric distentions using an electronic barostat. The bag was progressively distended from 0 to 48 mm Hg and, in response to distention, subjects reported on discomfort or pain. RESULTS: Pain thresholds were lower in IBS patients (30.4 +/- 6.7 mm Hg) compared with controls (44.5 +/- 5), painless constipated (45.4 +/- 5.3), functional dyspepsia (39.4 +/- 7.8), and miscellaneous patients (43.2 +/- 5.5). At the level of 40 mm Hg, the sensitivity of the rectal barostat to identify IBS patients from normal subjects and non-IBS patients was 95.5% and its specificity was 71.8%. The positive predictive value was 85.4%. The negative predictive value was 90.2%. CONCLUSIONS: Lowered rectal pain threshold is a hallmark of IBS patients. Rectal barostat testing is useful to confirm the diagnosis of IBS and to discriminate IBS from other causes of abdominal pain.
