Bharucha, Adil E.

AbstractBackgroundThis study compared the effects of ondansetron and placebo in patients with diabetes mellitus and symptoms of dyspepsia (diabetic gastroenteropathy [DGE]).MethodsWe performed a randomized, double‐blinded, placebo‐controlled study of ondansetron tablets (8 mg) three times daily for 4 weeks in DGE patients. Symptoms were assessed with the Gastroparesis Cardinal Symptom Index daily diaries. Gastric emptying (GE) of solids (scintigraphy) and duodenal lipid infusions (300 kcal over 2 h) were each assessed twice, with placebo and ondansetron. Drug effects on GE, symptoms during the GE study and during lipid infusion, and daily symptoms were analyzed.Key ResultsOf 41 patients, 37 completed both GE studies and one completed 1; 31 completed both lipid infusions and four only placebo; and all 35 randomized patients completed 4 weeks of treatment. Compared to placebo, ondansetron reduced the severity of fullness (p = 0.02) and belching (p = 0.049) during lipid infusion but did not affect GE T1/2. Both ondansetron and placebo improved daily symptoms versus the baseline period (p < 0.05), but the differences were not significant. In the analysis of covariance of daily symptoms during the treatment period, the interaction term between treatment and the acute effect of ondansetron on symptoms during lipid challenge was significant (p = .024).Conclusions & InferencesOndansetron significantly reduced fullness during enteral lipid infusion in patients with DGE. Overall, ondansetron did not improve daily symptoms versus placebo. But patients in whom ondansetron improved symptoms during enteral lipid challenge were perhaps more likely to experience symptom relief during daily treatment.

Abstract Background Although diabetic gastroenteropathy (DGE) is associated with small intestinal bacterial overgrowth (SIBO), most studies have evaluated SIBO with a hydrogen breath test, which may be affected by altered transit in DGE. The risk factors for the consequences of SIBO in DGE are poorly understood. We aimed to evaluate the prevalence of, risk factors for, and gastrointestinal symptoms associated with SIBO in patients with DGE. Methods In 75 patients with DGE and dyspepsia, we tested for SIBO (≥10 5 colony forming units /mL of aerobic and/or anaerobic bacteria in a duodenal aspirate) and assessed gastric emptying (GE) of solids, symptoms during a GE study and during an enteral lipid challenge (300 kcal/2 h), and daily symptoms with a Gastroparesis Cardinal Symptom Index diary for 2 weeks. Symptoms and GE were compared in patients with versus without SIBO. Key Results Of 75 patients, 34 (45%) had SIBO, which was not associated with the use of proton pump inhibitors, daily symptoms, GE, or symptoms during a GE study. During enteral lipid challenge, severe nausea ( p = 0.006), fullness ( p = 0.02) and bloating ( p = 0.009) were each associated with SIBO. Twenty patients (59%) with versus 13 (32%) without SIBO had at least one severe symptom during the lipid challenge ( p = 0.006). Conclusions & Inferences Among patients with DGE 45% had SIBO, which was associated with symptoms during enteral lipid challenge but not with delayed GE, symptoms during a GE study, or daily symptoms. Perhaps bacterial products and even fatty acids are recognized by and activate mast cells that drive the increased lipid sensitivity in SIBO.

AbstractBackground and AimsUp to 50% of patients with Parkinson disease have constipation (PD‐C), but the prevalence of defecatory disorders caused by rectoanal dyscoordination in PD‐C is unknown. We aimed to compare anorectal function of patients with PD‐C versus idiopathic chronic constipation (CC).MethodsAnorectal pressures, rectal sensation, and rectal balloon expulsion time (BET) were measured with high‐resolution anorectal manometry (HR‐ARM) in patients with PD‐C and control patients with CC, matched for age and sex.ResultsWe identified 97 patients with PD‐C and 173 control patients. Eighty‐six patients with PD‐C (89%) had early PD, and 39 (40%) had a defecatory disorder, manifest by a prolonged rectal balloon expulsion time (37 patients) or a lower rectoanal pressure difference during evacuation (2 patients). PD‐C patients with a prolonged BET had a greater anal resting pressure (p = 0.02), a lower rectal pressure increment (p = 0.005), greater anal pressure (p = 0.047), and a lower rectoanal pressure difference during evacuation (p < 0.001). Rectal sensory thresholds were greater in patients with abnormal BET.In the multivariate model comparing CC and PD‐C (AUROC = 0.76), PD‐C was associated with a lower anal squeeze increment (odds ratio [OR] for PD‐C, 0.93 [95% CI, 0.91–0.95]), longer squeeze duration (OR, 1.05 [95% CI, 1.03–1.08]), lower rectal pressure increment (OR per 10 mm Hg, 0.72 [95% CI, 0.66–0.79]), and negative rectoanal gradient during evacuation (OR per 10 mm Hg, 1.16 [95% CI, 1.08–1.26]).ConclusionsCompared with CC, PD‐C was characterized by impaired squeeze pressure, longer squeeze duration, lower increase in rectal pressure, and a more negative rectoanal gradient during evacuation.

AbstractBackgroundHow variations predicted by pharmacogenomic testing to alter drug metabolism and therapeutic response affect outcomes for patients with disorders of gut‐ brain interaction is unclear.AimsTo assess the prevalence of pharmacogenomics‐predicted drug‐gene interactions and symptom outcomes for patients with disorders of gut‐brain interaction.MethodsPatients who were treated in our clinical practice for functional dyspepsia/bowel disorder underwent pharmacogenomic testing. The change in symptoms from baseline to 6 months was compared for patients with variations in CYP2D6 and CYP2C19, which metabolize neuromodulators, and SLC6A4, which encodes the sodium‐ dependent serotonin transporter.ResultsAt baseline, 79 of 94 participants (84%) had at least one predicted major drug‐ gene interaction, and all 94 (100%) had at least one predicted moderate interaction. For the 44 participants who completed a survey of their symptoms at 6 months, the mean (SD) irritable bowel syndrome‐symptom severity score decreased from 284 (71) at baseline to 231 (95) at 6 months (p < 0.001). Among patients taking selective serotonin reuptake inhibitors, the decrease in symptom severity (p = 0.03) and pain (p = 0.002) scores from baseline to 6 months was greater for patients with a homozygous SLC6A4 long/long genotype (n = 30) (ie, increased serotonin transporter activity) than for patients with homozygous short/short or heterozygous long/short genotypes (n = 64). Symptom outcomes were not affected by CYP2D6 or CYP2C19 variations.ConclusionsThe homozygous SLC6A4 long/long genotype confers better symptom resolution for patients with disorders of gut‐brain interaction who take selective serotonin reuptake inhibitors than do the homozygous short/short or heterozygous long/short genotypes.

AbstractBackgroundDiarrhea and rectal urgency are risk factors for fecal incontinence (FI). The effectiveness of bowel modifiers for improving FI is unclear.MethodsIn this double‐blind, parallel‐group, randomized trial, women with urge FI were randomly assigned in a 1:1 ratio to a combination of oral clonidine (0.1 mg twice daily) with colesevelam (1875 mg twice daily) or two inert tablets for 4 weeks. The primary outcome was a ≥50% decrease in number of weekly FI episodes.Key ResultsFifty‐six participants were randomly assigned to clonidine–colesevelam (n = 24) or placebo (n = 32); 51 (91%) completed 4 weeks of treatment. At baseline, participants had a mean (SD) of 7.5 (8.2) FI episodes weekly. The primary outcome was met for 13 of 24 participants (54%) treated with clonidine–colesevelam versus 17 of 32 (53%) treated with placebo (p = 0.85). The Bristol stool form score decreased significantly, reflecting more formed stools with clonidine–colesevelam treatment (mean [SD], 4.5 [1.5] to 3.2 [1.5]; p = 0.02) but not with placebo (4.2 [1.9] to 4.1 [1.9]; p = 0.47). The proportion of FI episodes for semiformed stools decreased significantly from a mean (SD) of 76% (8%) to 61% (10%) in the clonidine–colesevelam group (p = 0.007) but not the placebo group (61% [8%] to 67% [8%]; p = 0.76). However, these treatment effects did not differ significantly between groups. Overall, clonidine–colesevelam was well tolerated.Conclusions and InferencesCompared with placebo, clonidine–colesevelam did not significantly improve FI despite being associated with more formed stools and fewer FI episodes for semiformed stools.