Dysmotility and proton pump inhibitor use are independent risk factors for small intestinal bacterial and/or fungal overgrowth.

BACKGROUND: Whether intestinal dysmotility and the use of a proton pump inhibitor (PPI) either independently or together contributes to small intestinal bacterial overgrowth (SIBO), and/or small intestinal fungal overgrowth (SIFO) is not known. AIM: To investigate the role of dysmotility and PPI use in patients with persistent gastrointestinal complaints. METHODS: Patients with unexplained gastrointestinal symptoms and negative endoscopy/radiology tests completed a validated symptom questionnaire and underwent 24-h ambulatory antro-duodeno-jejunal manometry (ADJM). Simultaneously, duodenal aspirate was obtained for aerobic, anaerobic and fungal culture. Dysmotility was diagnosed by (>2): absent phase III MMC, absent/diminished postprandial response, diminished amplitude of antral/intestinal phasic activity, impaired antro-duodenal coordination. Bacterial growth ≥10³ CFU/mL or fungal growth was considered evidence for SIBO/SIFO. PPI use was documented. Correlation of symptoms with presence of SIBO or SIFO was assessed. RESULTS: One hundred and fifty subjects (M/F = 47/103) were evaluated; 94/150 (63%) had overgrowth: 38/94 (40%) had SIBO, 24/94 (26%) had SIFO and 32/94 (34%) had mixed SIBO/SIFO. SIBO was predominately due to Streptococcus, Enterococcus, Klebsiella and E. coli. SIFO was due to Candida. Eighty of 150 (53%) patients had dysmotility and 65/150 (43%) used PPI. PPI use (P = 0.0063) and dysmotility (P = 0.0003) were independent significant risk factors (P < 0.05) for overgrowth, but together did not pose additional risk. Symptom profiles were similar between those with or without SIBO/SIFO. CONCLUSIONS: Dysmotility and PPI use were independent risk factors for SIBO or SIFO and were present in over 50% of subjects with unexplained gastrointestinal symptoms. Diagnosis of overgrowth requires testing because symptoms were poor predictors of overgrowth.

Diagnostic utility of the oesophageal balloon distension test in the evaluation of oesophageal chest pain.

BACKGROUND: Oesophageal balloon distension test (EBDT) has been advocated for the evaluation of functional oesophageal noncardiac chest pain (NCCP), but its diagnostic utility remains unclear. AIM: To prospectively assess the diagnostic yield of EBDT in clinical practice and compare its yield with standard oesophageal tests. METHODS: Over a period of 6 years, patients with chest pain and negative cardiac work-up underwent sequential testing with endoscopy/biopsy, oesophageal manometry, 24 h pH study and EBDT to elucidate an oesophageal source for their symptoms. Patients with a definite abnormality, for example, erosive oesophagitis on oesophagogastroduodenoscopy (EGD) were designated as having positive test and excluded from further work up. RESULTS: Of 348 (m/f = 105/243) suspected NCCP patients, 16 (5%) were excluded; 332 (95%) underwent oesophageal testing. Among these, 48 (14%) had macro/microscopic oesophagitis on endoscopy, 7 (2%) had achalasia and 96 (28%) had excessive acid reflux (pH study). The remaining 181 (52%) patients underwent EBDT; 128 (37%) had oesophageal hypersensitivity. Chest pain was reproduced in 97/128 (75%) subjects. There were no adverse effects. CONCLUSIONS: Oesophageal testing can reveal an oesophageal source for chest pain in 86% of NCCP subjects. The majority (42%) of patients had gastro-oesophageal reflux disease (GERD). Oesophageal balloon distension test identified hypersensitivity in over one-third of subjects. The oesophageal balloon distension test provides useful diagnostic information and should be performed routinely in patients with NCCP after excluding GERD.

Barostat or dynamic balloon distention test: which technique is best suited for esophageal sensory testing?

Esophageal sensation is commonly assessed by barostat-assisted balloon distension (BBD) or dynamic balloon distension (DBD) technique, but their relative merits are unknown. Our aim was to compare the usefulness and tolerability of both techniques. Sixteen healthy volunteers (male/female = 6/10) randomly underwent graded esophageal balloon distensions, using either BBD (n= 8) or DBD (n= 8). BBD was performed by placing a 5-cm long highly compliant balloon attached to a barostat, and DBD by placing a 5-cm long balloon attached to a leveling container. Intermittent phasic balloon distensions were performed in increments of 6 mm Hg. Sensory thresholds and biomechanical properties were assessed and compared. Sensory thresholds for first perception (mean ± standard deviation; 21 ± 6 vs. 21.2 ± 5, mm Hg, P= 0.9), discomfort (38 ± 8 vs. 35 ± 9, P= 0.5), and pain (44 ± 4 vs. 45 ± 3, P= 0.7) were similar with BBD and DBD techniques. However, more subjects tolerated DBD (7/8, 88%) when compared with BBD (4/8, 50%). Forceful expulsion of balloon into stomach (n= 4), pulling around the mouth (n= 4), chest discomfort (n= 2) and retching (n= 2) were overlapping reasons for intolerance with BBD. Esophageal wall distensibility was similar with both techniques. Both techniques provided comparable data on biomechanical properties. However, DBD was better tolerated than BBD for evaluation of esophageal sensation. Hence, we recommend DBD for performing esophageal balloon distension test.

Randomised clinical trial: dried plums (prunes) vs. psyllium for constipation.

BACKGROUND: Treatment of chronic constipation remains challenging with 50% of patients dissatisfied with current therapy. There is an unmet need for natural and safe alternatives. Dried plums (prunes) have been used traditionally for constipation but their efficacy is not known. Aim To assess and compare the effects of dried plums and psyllium in patients with chronic constipation. METHODS: Subjects were enrolled in an 8-week, single-blind, randomised cross-over study. Subjects received either dried plums (50 g b.d., fibre=6 gm/day) or psyllium (11 g b.d., fibre=6 gm/day) for 3 weeks each, in a crossover trial with a 1-week washout period. Subjects maintained a daily symptom and stool diary. Assessments included number of complete spontaneous bowel movements per week, global relief of constipation, stool consistency, straining, tolerability and taste. RESULTS: Forty constipated subjects (m/f=3/37, mean age=38 years) participated. The number of complete spontaneous bowel movements per week (primary outcome measure) and stool consistency scores improved significantly (P<0.05) with dried plums when compared to psyllium. Straining and global constipation symptoms did not differ significantly between treatments (P=N.S.). Dried plums and psyllium were rated as equally palatable and both were safe and well tolerated. CONCLUSION: Dried plums are safe, palatable and more effective than psyllium for the treatment of mild to moderate constipation, and should be considered as a first line therapy.

A bi-directional assessment of the human brain-anorectal axis.

BACKGROUND: Brain-gut dysfunction has been implicated in gastrointestinal disorders but a comprehensive test of brain-gut axis is lacking. We developed and tested a novel method for assessing both afferent anorectal-brain function using cortical evoked potentials (CEP), and efferent brain-anorectal function using motor evoked potentials (MEP). METHODS: Cortical evoked potentials was assessed following electrical stimulations of anus and rectum with bipolar electrodes in 26 healthy subjects. Anorectal MEPs were recorded following transcranial magnetic stimulation (TMS) over paramedian motor cortices bilaterally. Anal and rectal latencies/amplitudes for CEP and MEP responses and thresholds for first sensation and pain (mA) were analyzed and compared. Reproducibility and interobserver agreement of responses were examined. KEY RESULTS: Reproducible polyphasic rectal and anal CEPs were recorded in all subjects, without gender differences, and with negative correlation between BMI and CEP amplitude (r -0.66, P=0.001). Transcranial magnetic stimulation evoked triphasic rectal and anal MEPs, without gender differences. Reproducibility for CEP and MEP was excellent (CV <10%). The inter-rater CV for anal and rectal MEPs was excellent (ICC 97-99), although there was inter-subject variation. CONCLUSIONS & INFERENCES: Combined CEP and MEP studies offer a simple, inexpensive and valid method of examining bidirectional brain-anorectal axes. This comprehensive method could provide mechanistic insights into lower gut disorders.

Investigation of esophageal sensation and biomechanical properties in functional chest pain.

BACKGROUND: There is limited and conflicting data regarding the role of esophageal hypersensitivity in the pathogenesis of functional chest pain (FCP). We examined esophageal sensori-motor properties, mechanics, and symptoms in subjects with FCP. METHODS: Esophageal balloon distension test was performed using impedance planimetry in 189 (m/f = 57/132) consecutive subjects with non-cardiac, non-reflux chest pain, and 36 (m/f = 16/20) healthy controls. The biomechanical and sensory properties of subjects with and without esophageal hypersensitivity were compared with controls. The frequency, intensity, and duration of chest pain were assessed. KEY RESULTS: One hundred and forty-three (75%) subjects had esophageal hypersensitivity and 46 (25%) had normal sensitivity. Typical chest pain was reproduced in 105/143 (74%) subjects. Subjects with hypersensitivity demonstrated larger cross-sectional area (P < 0.001), decreased esophageal wall strain (P < 0.001) and distensibility (P < 0.001), and lower thresholds for perception (P < 0.01), discomfort (P < 0.01), and pain (P < 0.01) compared to those without hypersensitivity or healthy controls. Chest pain scores (mean +/- SD) for frequency, intensity and duration were 2.5 +/- 0.3, 2.2 +/- 0.2, and 2.2 +/- 0.2, respectively, and were similar between the two patient groups. CONCLUSIONS & INFERENCES: Seventy-five per cent of subjects with FCP demonstrate esophageal hypersensitivity. Visceral hyperalgesia and sensori-motor dysfunction of the esophagus play a key role in the pathogenesis of chest pain.

Visceral hypersensitivity and impaired accommodation in refractory diabetic gastroparesis.

The pathophysiology of persistent gastrointestinal (GI) symptoms in patients with diabetic gastroparesis is poorly understood. Our aim was to evaluate gastric sensation and accommodation to a meal in patients with diabetic gastroparesis and refractory symptoms. We performed intermittent, phasic balloon distensions of the stomach using a gastric barostat device in 18 patients with diabetes and gastroparesis unresponsive to prokinetic therapy and in 13 healthy volunteers. We assessed the biomechanical, sensory and accommodation responses of the stomach, during fasting and after liquid meal. During balloon distension, the sensory thresholds for discomfort were lower (P < 0.02) in patients with diabetes than those in controls, in both the fasting and the postprandial states. The accommodation response to a meal was significantly impaired (P = 0.01) in patients with diabetes when compared to controls, although fasting gastric tone was similar (P = 0.08). Patients with diabetic gastroparesis and refractory GI symptoms demonstrate sensori-motor dysfunction of the stomach, comprising either impaired accommodation, gastric hypersensitivity or both. An objective evaluation of these biomechanical and sensory properties may provide valuable mechanistic insights that could guide therapy.