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S1262 High-Resolution Colonic Manometry: Have We Been Incorrectly Labeling Colonic Motor Patterns?
AGA Abstracts
bowel, a distal to proximal colonic regional shift in the site of origin of PSs leading up to defecation was only observed on 6/21 (28%) of occasions compared to 9/10 (90%) in the unprepared bowel (P=0.001). A 1000 KCal meal induced a significant (P<0.01) increase in HAPS frequency when compared to basal period immediately preceding it in both groups. Comparison of the delta HAPS increase (postprandial - basal) between the two groups did not differ (prepared delta; 3.3 ± 2.8 v 2.0 ± 1.6 HAPS/2hr; NS). Conclusion: Prior cleansing of the healthy colon has no effect upon the frequency of antegrade and retrograde PSs, their site of origin, or the colonic response to a meal. There is, however, a significant increase in the frequency and amplitude of HAPSs and a significant alteration in the spatiotemporal patterning of pre-defecation PSs. These factors should be taken into consideration when comparing colonic data recorded via different techniques. Supported by NNHMRC Australia.
208 patients (77%), whereas 46 had accelerated (17%) and 16 delayed transit (6%). IBS subtyping according to the Rome III criteria was associated with abnormal CTT (p<0.0001) - accelerated CTT was more commonly seen in IBS-D (diarrhea) (31%), whereas delayed CTT was more common in IBS-C (constipation) (14%). In line with this the mean CTT was shortest in IBS-D (1.3±0.7 (mean±SD) days), followed by the combined group with IBS-M (mixed) and IBS-U (unsubtyped) (1.6±0.9 days), and IBS-C (2.3±1.3 days) (p<0.0001). Transit abnormalities, based on normal values, were more common in males than in females (33% vs. 19%; p<0.05), and CTT was faster in males (1.3±0.8 vs. 1.7±1.1 days; p<0.01). CTT was associated with the average stool frequency (r=-0.28; p<0.0001) and consistency (r=-0.39; p<0.0001). When assessing the proportion of different stool forms according to BSF, the strongest correlations were seen between CTT and the proportion of hard/lumpy stools (BSF 1-2; r=0.42; p<0.0001) or loose/watery stools (BSF 6-7; r=-0.35; p<0.0001). CTT was associated with the severity of diarrhea (r=-0.38; p<0.0001), whereas weaker, but statistically significant associations were found between CTT and the severity of constipation (r=0.22; p<0.05) and abdominal pain (-0.18; p<0.05). No associations were seen between CTT and other GI symptoms, quality of life, age, anxiety or depression. Conclusion: Colonic transit alterations are of importance for the abnormal bowel habit seen in men and women with IBS. However, it does not seem to be associated with other GI symptoms, quality of life or psychological symptoms to any meaningful extent.
S1260 Reproducibility and Performance Characteristics of Colonic Compliance, Tone and Sensory Functions in Healthy Volunteers Suwebatu T. Odunsi, Michael Camilleri, Adil E. Bharucha, Duane D. Burton, Irene Busciglio, Alan R. Zinsmeister Background: The performance characteristics of colonic compliance, tone and sensation measurements used in physiological and pharmacodynamic studies in healthy volunteers are unclear. Aim: To evaluate inter- and intra-individual coefficient of variation (COV) of left colon compliance, tone and sensation in humans. Methods: This study was based on data acquired in different pharmacodynamic studies using standard barostat methods, by one technologist, in 72 human volunteers (38 males, aged 18-65 y). When the studies were conducted, treatment was double-blinded. All participants underwent examinations of compliance, fasting tone and sensation during baseline and post-placebo; postprandial tone was measured only post-placebo. Intubation was achieved with unsedated, limited colonoscopy and fluoroscopy. Compliance was measured using ascending method of limits over 064 mmHg and linear interpolation of the pressure volume curves to identify pressure at half maximum volume (Pr50). Sensory threshold for first sensation, gas and pain were recorded. Sensory ratings (0-100 mm VAS) were measured during random order phasic distensions at pressures 8 to 36 mmHg above baseline operating pressure. Change in postprandial (PP) barostat balloon volume for the first 30 min after a 1000kcal meal assessed motor response. Inter-coefficient of variation (COV) was calculated as 100 (SD/mean), and intra-COV as (100*SD delta/overall mean). Results: Data are summarized in table [COV intra NA (= not available) for PP tone]. Mean and SD of baseline measurements are provided; COV are generally lower for compliance, fasting tone, pain threshold, and sensation ratings than for PP tone and threshold for first or gas sensation. COV data are similar in males and females; sensation COVs appear smaller in females relative to males. Conclusions: Testing of compliance, tone and pain and gas sensation in left colon performs adequately to assess these colonic functions in humans. Data provide the basis for calculating sample sizes for future studies. The lower COV for sensation tests among females is relevant to plan pharmacodynamic studies of drugs intended for patients with functional GI disorders.
S1262 High-Resolution Colonic Manometry: Have We Been Incorrectly Labeling Colonic Motor Patterns? Philip G. Dinning, John W. Arkwright, Michal M. Szczesniak, Sergio E. Fuentealba, Neil Blenman, Ian Underhil, Simon Maunder, Ian J. Cook Colonic manometry has defined dysmotility in patients with constipation, yet correlation with patient symptoms remains elusive; as does the identification of a specific biomarker to define constipation subtypes. Typically colonic manometry is recorded with sidehole spacing ≥7cm, however propagated sequences (PS) in the colon can extend over segments as short as 3cm,. Thus in practice, we have been measuring manometric patterns at spacing up to twice that of many of the propagated events which can lead to mislabeling of many of the events of interest. Aim: To determine if accurate identification of PSs is dependant upon the spatial-resolution of recording sites by implementing an innovative fibre-optic sensing catheter containing 32 pressure sensing elements spaced at 1cm. Method: The catheter, previously validated in the oesophagus, was introduced colonoscopically to the midtransverse colon in a female patient with scintigraphically confirmed slow transit constipation. Three hours of colonic manometry was recorded, prior to and following a 1000kCal meal (6hrs in total). The resulting data was analysed in 4 different ways by sub-sampling different sets of the full array to simulate different sensor spacing and also different apparent locations of the 7cm spaced data. . The following data sets were used: Setting A; 10cm spacing (sensor 1, 11, 21, 31), Setting B; 7cm spacing (sensors 1, 8, 15, 22, 29), Setting C; 7cm spacing (sensors 3, 10, 17, 24, 31), Setting D; 1cm spacing (all sensors). For each setting antegrade and retrograde PSs (APS & RPS) and high amplitude propagating sequences (HAPS) were identified. Results: Using setting D as the Gold Standard, between 32-40% of PSs were identified incorrectly in each of the other settings. All of the HAPS in C were wrongly identified. In one instance 2 retrograde PS's identified in D were wrongly identified as a single antegrade PS in B & C. The table highlights the variability in detecting the frequency of PSs and HAPSs using the different sensor spacing. Conclusion: This study indicates the potential to miss and/or mislabel colonic PSs if inadequate sensor spacing is used. High resolution colonic manometry may help us to correctly identify specific biomarkers that will help to define colonic disorders and ultimately guide treatment. Frequency of propagated sequences identified with different sensor spacing
S1263 Irritable Bowel Syndrome Diagnosed By ROME III Criteria Is Not Associated with Visceral Hypersensitivity Determined By Rectal Barostat Distension: A Prospective Study Viola Andresen, Henning Hohendorf, Aleksandr Sumenko, Jutta Keller, Peter H. Layer Background: Visceral hypersensitivity (VH), reflected by lower pain thresholds during rectal distension, is considered a pivotal pathogenic factor in the irritable bowel syndrome (IBS). In patients with chronic GI symptoms, IBS (Rome II) was detected at graded pain thresholds with sensitivity / specificity rates of: 28 mmHg: 63% / 100%; 32 mmHg: 77% / 92%; 40mmHg: 91% / 80% [1]. If these thresholds are associated with IBS diagnosed by the new Rome III criteria is unknown. Aim: To test whether these thresholds can identify IBS according to Rome III criteria in patients with pertinent GI symptoms. Methods: 39 consecutive patients with chronic lower GI tract symptoms and no evidence of structural disease by history, laboratory or endoscopy underwent a series of rectal isobaric balloon distension tests. Pressures between 0 to 48 mmHg were applied using an electronic barostat following the protocol by Bouin et al. [1]. Pain thresholds were assessed recording the patients' rectal sensations (ranging from 0=”no sensation” to 7=”pain”) in response to each distension. IBS was diagnosed by the Rome III questionnaire for the diagnosis of functional gastrointestinal diseases. Investigators of barostat tests were blinded to the questionnaires' results. Statistics included ANOVA and Pearson ChiSquare tests. Results: 69% (n=27) of the patients met the diagnosis of IBS (Rome III criteria). VH, defined by pain threshold categories of 28, 32 or 40 mmHg, was present in 36% (n=14), 47% (n=24) or 69% (n=27) of the patients respectively. There was no relationship between any VH category and IBS. The distribution of pain
S1261 Colonic Transit Time Influences the Abnormal Bowel Habit, But Not Other Gastrointestinal Symptoms, in Irritable Bowel Syndrome Riadh Sadik, Iris Posserud, Hans Strid, Gisela Ringstrom, Pia Agerforz, Hasse Abrahamsson, Magnus Simren Background: Abnormal colonic transit has been proposed to be the most common physiologic abnormality in irritable bowel syndrome (IBS) (Camilleri et al CGH 2008). The relevance of abnormal colonic transit for the symptom pattern and quality of life in IBS remains to be established. Aim: To measure colonic transit time (CTT) in a large group of IBS patients and to assess the relationship with symptoms, demographic factors and quality of life. Methods: CTT was assessed using radiopaque markers (Sadik et al SJG 2003) in 270 patients with IBS (mean age 39 (19-69) years; 202 females). These results were compared with normal values for healthy men and women without GI symptoms. The patients recorded stool frequency and consistency (Bristol Stool Form (BSF) scale) during the measurement week. They also completed questionnaires to assess GI (Gastrointestinal Symptom Rating Scale or IBS Severity Scoring System) and psychological symptom severity (Hospital Anxiety and Depression Scale), and quality of life (IBSQOL). Results: Normal CTT was found in
AGA Abstracts
A-224
bowel, a distal to proximal colonic regional shift in the site of origin of PSs leading up to defecation was only observed on 6/21 (28%) of occasions compared to 9/10 (90%) in the unprepared bowel (P=0.001). A 1000 KCal meal induced a significant (P<0.01) increase in HAPS frequency when compared to basal period immediately preceding it in both groups. Comparison of the delta HAPS increase (postprandial - basal) between the two groups did not differ (prepared delta; 3.3 ± 2.8 v 2.0 ± 1.6 HAPS/2hr; NS). Conclusion: Prior cleansing of the healthy colon has no effect upon the frequency of antegrade and retrograde PSs, their site of origin, or the colonic response to a meal. There is, however, a significant increase in the frequency and amplitude of HAPSs and a significant alteration in the spatiotemporal patterning of pre-defecation PSs. These factors should be taken into consideration when comparing colonic data recorded via different techniques. Supported by NNHMRC Australia.
208 patients (77%), whereas 46 had accelerated (17%) and 16 delayed transit (6%). IBS subtyping according to the Rome III criteria was associated with abnormal CTT (p<0.0001) - accelerated CTT was more commonly seen in IBS-D (diarrhea) (31%), whereas delayed CTT was more common in IBS-C (constipation) (14%). In line with this the mean CTT was shortest in IBS-D (1.3±0.7 (mean±SD) days), followed by the combined group with IBS-M (mixed) and IBS-U (unsubtyped) (1.6±0.9 days), and IBS-C (2.3±1.3 days) (p<0.0001). Transit abnormalities, based on normal values, were more common in males than in females (33% vs. 19%; p<0.05), and CTT was faster in males (1.3±0.8 vs. 1.7±1.1 days; p<0.01). CTT was associated with the average stool frequency (r=-0.28; p<0.0001) and consistency (r=-0.39; p<0.0001). When assessing the proportion of different stool forms according to BSF, the strongest correlations were seen between CTT and the proportion of hard/lumpy stools (BSF 1-2; r=0.42; p<0.0001) or loose/watery stools (BSF 6-7; r=-0.35; p<0.0001). CTT was associated with the severity of diarrhea (r=-0.38; p<0.0001), whereas weaker, but statistically significant associations were found between CTT and the severity of constipation (r=0.22; p<0.05) and abdominal pain (-0.18; p<0.05). No associations were seen between CTT and other GI symptoms, quality of life, age, anxiety or depression. Conclusion: Colonic transit alterations are of importance for the abnormal bowel habit seen in men and women with IBS. However, it does not seem to be associated with other GI symptoms, quality of life or psychological symptoms to any meaningful extent.
S1260 Reproducibility and Performance Characteristics of Colonic Compliance, Tone and Sensory Functions in Healthy Volunteers Suwebatu T. Odunsi, Michael Camilleri, Adil E. Bharucha, Duane D. Burton, Irene Busciglio, Alan R. Zinsmeister Background: The performance characteristics of colonic compliance, tone and sensation measurements used in physiological and pharmacodynamic studies in healthy volunteers are unclear. Aim: To evaluate inter- and intra-individual coefficient of variation (COV) of left colon compliance, tone and sensation in humans. Methods: This study was based on data acquired in different pharmacodynamic studies using standard barostat methods, by one technologist, in 72 human volunteers (38 males, aged 18-65 y). When the studies were conducted, treatment was double-blinded. All participants underwent examinations of compliance, fasting tone and sensation during baseline and post-placebo; postprandial tone was measured only post-placebo. Intubation was achieved with unsedated, limited colonoscopy and fluoroscopy. Compliance was measured using ascending method of limits over 064 mmHg and linear interpolation of the pressure volume curves to identify pressure at half maximum volume (Pr50). Sensory threshold for first sensation, gas and pain were recorded. Sensory ratings (0-100 mm VAS) were measured during random order phasic distensions at pressures 8 to 36 mmHg above baseline operating pressure. Change in postprandial (PP) barostat balloon volume for the first 30 min after a 1000kcal meal assessed motor response. Inter-coefficient of variation (COV) was calculated as 100 (SD/mean), and intra-COV as (100*SD delta/overall mean). Results: Data are summarized in table [COV intra NA (= not available) for PP tone]. Mean and SD of baseline measurements are provided; COV are generally lower for compliance, fasting tone, pain threshold, and sensation ratings than for PP tone and threshold for first or gas sensation. COV data are similar in males and females; sensation COVs appear smaller in females relative to males. Conclusions: Testing of compliance, tone and pain and gas sensation in left colon performs adequately to assess these colonic functions in humans. Data provide the basis for calculating sample sizes for future studies. The lower COV for sensation tests among females is relevant to plan pharmacodynamic studies of drugs intended for patients with functional GI disorders.
S1262 High-Resolution Colonic Manometry: Have We Been Incorrectly Labeling Colonic Motor Patterns? Philip G. Dinning, John W. Arkwright, Michal M. Szczesniak, Sergio E. Fuentealba, Neil Blenman, Ian Underhil, Simon Maunder, Ian J. Cook Colonic manometry has defined dysmotility in patients with constipation, yet correlation with patient symptoms remains elusive; as does the identification of a specific biomarker to define constipation subtypes. Typically colonic manometry is recorded with sidehole spacing ≥7cm, however propagated sequences (PS) in the colon can extend over segments as short as 3cm,. Thus in practice, we have been measuring manometric patterns at spacing up to twice that of many of the propagated events which can lead to mislabeling of many of the events of interest. Aim: To determine if accurate identification of PSs is dependant upon the spatial-resolution of recording sites by implementing an innovative fibre-optic sensing catheter containing 32 pressure sensing elements spaced at 1cm. Method: The catheter, previously validated in the oesophagus, was introduced colonoscopically to the midtransverse colon in a female patient with scintigraphically confirmed slow transit constipation. Three hours of colonic manometry was recorded, prior to and following a 1000kCal meal (6hrs in total). The resulting data was analysed in 4 different ways by sub-sampling different sets of the full array to simulate different sensor spacing and also different apparent locations of the 7cm spaced data. . The following data sets were used: Setting A; 10cm spacing (sensor 1, 11, 21, 31), Setting B; 7cm spacing (sensors 1, 8, 15, 22, 29), Setting C; 7cm spacing (sensors 3, 10, 17, 24, 31), Setting D; 1cm spacing (all sensors). For each setting antegrade and retrograde PSs (APS & RPS) and high amplitude propagating sequences (HAPS) were identified. Results: Using setting D as the Gold Standard, between 32-40% of PSs were identified incorrectly in each of the other settings. All of the HAPS in C were wrongly identified. In one instance 2 retrograde PS's identified in D were wrongly identified as a single antegrade PS in B & C. The table highlights the variability in detecting the frequency of PSs and HAPSs using the different sensor spacing. Conclusion: This study indicates the potential to miss and/or mislabel colonic PSs if inadequate sensor spacing is used. High resolution colonic manometry may help us to correctly identify specific biomarkers that will help to define colonic disorders and ultimately guide treatment. Frequency of propagated sequences identified with different sensor spacing
S1263 Irritable Bowel Syndrome Diagnosed By ROME III Criteria Is Not Associated with Visceral Hypersensitivity Determined By Rectal Barostat Distension: A Prospective Study Viola Andresen, Henning Hohendorf, Aleksandr Sumenko, Jutta Keller, Peter H. Layer Background: Visceral hypersensitivity (VH), reflected by lower pain thresholds during rectal distension, is considered a pivotal pathogenic factor in the irritable bowel syndrome (IBS). In patients with chronic GI symptoms, IBS (Rome II) was detected at graded pain thresholds with sensitivity / specificity rates of: 28 mmHg: 63% / 100%; 32 mmHg: 77% / 92%; 40mmHg: 91% / 80% [1]. If these thresholds are associated with IBS diagnosed by the new Rome III criteria is unknown. Aim: To test whether these thresholds can identify IBS according to Rome III criteria in patients with pertinent GI symptoms. Methods: 39 consecutive patients with chronic lower GI tract symptoms and no evidence of structural disease by history, laboratory or endoscopy underwent a series of rectal isobaric balloon distension tests. Pressures between 0 to 48 mmHg were applied using an electronic barostat following the protocol by Bouin et al. [1]. Pain thresholds were assessed recording the patients' rectal sensations (ranging from 0=”no sensation” to 7=”pain”) in response to each distension. IBS was diagnosed by the Rome III questionnaire for the diagnosis of functional gastrointestinal diseases. Investigators of barostat tests were blinded to the questionnaires' results. Statistics included ANOVA and Pearson ChiSquare tests. Results: 69% (n=27) of the patients met the diagnosis of IBS (Rome III criteria). VH, defined by pain threshold categories of 28, 32 or 40 mmHg, was present in 36% (n=14), 47% (n=24) or 69% (n=27) of the patients respectively. There was no relationship between any VH category and IBS. The distribution of pain
S1261 Colonic Transit Time Influences the Abnormal Bowel Habit, But Not Other Gastrointestinal Symptoms, in Irritable Bowel Syndrome Riadh Sadik, Iris Posserud, Hans Strid, Gisela Ringstrom, Pia Agerforz, Hasse Abrahamsson, Magnus Simren Background: Abnormal colonic transit has been proposed to be the most common physiologic abnormality in irritable bowel syndrome (IBS) (Camilleri et al CGH 2008). The relevance of abnormal colonic transit for the symptom pattern and quality of life in IBS remains to be established. Aim: To measure colonic transit time (CTT) in a large group of IBS patients and to assess the relationship with symptoms, demographic factors and quality of life. Methods: CTT was assessed using radiopaque markers (Sadik et al SJG 2003) in 270 patients with IBS (mean age 39 (19-69) years; 202 females). These results were compared with normal values for healthy men and women without GI symptoms. The patients recorded stool frequency and consistency (Bristol Stool Form (BSF) scale) during the measurement week. They also completed questionnaires to assess GI (Gastrointestinal Symptom Rating Scale or IBS Severity Scoring System) and psychological symptom severity (Hospital Anxiety and Depression Scale), and quality of life (IBSQOL). Results: Normal CTT was found in
AGA Abstracts
A-224