Chial, Heather J.

To compare the effects of the κ-opioid agonist asimadoline and placebo on visceral sensation and gastrointestinal (GI) motor functions in humans, 91 healthy participants were randomized in a double-blind fashion to 0.15, 0.5, or 1.5 mg of asimadoline or placebo orally twice a day for 9 days. We assessed satiation (nutrient drink test), colonic compliance, tone, perception of colonic distension (barostat), and whole gut transit (scintigraphy). Treatment effect was assessed by analysis of covariance. Asimadoline increased nutrient drink intake ( P = 0.03). Asimadoline decreased colonic tone during fasting ( P = 0.03) without affecting postprandial colonic contraction, compliance, or transit. Gas scores in response to colonic distension were decreased with 0.5 mg of asimadoline at low levels (8 mmHg above operating pressure) of distension ( P = 0.04) but not at higher levels of distension. Asimadoline at 1.5 mg increased gas scores at 16 mmHg of distension ( P = 0.03) and pain scores at distensions of 8 and 16 mmHg ( P = 0.003 and 0.03, respectively) but not at higher levels of distension. Further studies of this compound in diseases with altered satiation or visceral sensation are warranted.

This study evaluated the effects of serotonergic psychoactive agents on gastrointestinal functions in healthy human subjects. Participants received one of four regimens in a randomized, double-blind manner: buspirone, a 5-HT 1A receptor agonist (10 mg twice daily); paroxetine, a selective serotonin reuptake inhibitor (20 mg daily); venlafaxine-XR, a selective serotonin and norepinephrine reuptake inhibitor (75 mg daily); or placebo for 11 days. Physiological testing performed on days 8–11included scintigraphic assessment of gastrointestinal and colonic transit, the nutrient drink test, and assessment of the postprandial change in gastric volume. Fifty-one healthy adults (40 females, 11 males) participated in this study. No effects on gastric emptying or colonic transit were identified with any agent. Small bowel transit of a solid meal was accelerated by paroxetine. Buspirone decreased postprandial aggregate symptom and nausea scores. Venlafaxine-XR increased the postprandial change in gastric volume. Buspirone, paroxetine, and venlafaxine-XR affect upper gastrointestinal functions in healthy humans. These data support the need for clinical and physiological studies of these agents in functional gastrointestinal disorders.

Objectives. To characterize the clinical features, results of diagnostic testing, and treatment outcomes for children and adolescents with rumination syndrome. Methods. Review of the medical records for all 147 patients ages 5 to 20 diagnosed with rumination syndrome at our institution between 1975 and 2000. Data are presented as mean ± the standard error of the mean. Results. Sixty-eight percent were female. Age at diagnosis was 15.0 ± 0.3 years. Symptom duration before diagnosis was 2.2 ± 0.3 years, 73% missed school/work, and 46% had been hospitalized because of symptoms. Before diagnosis, 16 (11%) underwent surgery for evaluation or management of symptoms. Twenty-four (16%) had psychiatric disorders; 3.4% had anorexia or bulimia nervosa. All patients described postprandial regurgitation after almost every meal (2.7 ± 0.1 meals per day). Weight loss was described by 42.2% (median: 7 kg). Additional symptoms included: abdominal pain, 38%; constipation, 21%; nausea, 17%; and diarrhea, 8%. Structural studies were normal. Gastric emptying of solids at 4 hours was delayed in 26 of 56 patients. Esophageal pH testing in 24 patients showed reflux/regurgitation in 54%. Gastroduodenal manometry in 65 patients showed characteristic rumination-waves in 40%. Outcome data (at median follow-up 10 months) were available for 54 patients. Symptoms resolved in 16 (30%) and improved in 30 (56%). Conclusions. Recognition of the clinical features of rumination syndrome in children and adolescents is essential; the diagnosis is often delayed and associated with morbidity. Extensive diagnostic testing is unnecessary. Early behavioral therapy is advocated, and patient outcomes are generally favorable.