Is malabsorption of fructose-sorbitol really important in the irritable bowel syndrome (IBS)?

(maximum 120 seconds).Time beforeappearanceof 1) discomfort, 2) pain and 3) withdrawing of the hand were noted. The intensity of pain was rated on a visual analogue scale (from 0 to 100). Self-report questionnaire were used to assess the severity of gastrointestinal symptoms (St-Luc GI index) and the psychological distress (SCL-90) in the patients group. Data are expressed in seconds as mean +_ SEM. Results: Discomfort sensory thresholds was similar in controls and FGID patients (28 _+ 3 and 24 +- 2 respectively; NS) whereas pain and withdrawing were significantly lower in FGID (41 -+ 3 and 76 _+ 6 s) than in controls (62 _+ 6 and 102 _+ 4; P
3230 Abdominal Wall Syndrome: A Cosily Diagnosis of Exclusion Christopher Thompson, Robert Goodman, William A. Rowe, Penn State Coil of Medicine, Hershey, PA Introduction: Abdominal wall syndromes (AWS)occur as the result of various abdominal wall pathologiescausing stimulation of a peripheralnerve. Patientswith abdominal wall syndrome are often subject to extensive diagnostic testing. We assessed medical resident awareness of this syndrome, determined the average cost of the diagnostic evaluation prior to trigger point injection (TPI). Methods: A written questionnaire was given to medical residents at a university hospital describing a classic presentation of AWS. Initial diagnostic study choice and rationale were determined. Separately,patients who received TPI in the gastroenterology clinic over the preceding year were reviewedretrospectivelyto determine the extent and cost of evaluation prior to TPI. Results: Of 23 residents surveyed, only 6 correctly identified AWS as the diagnosis in the patient presentedand favored TPI as initial intervention over abdominal ultrasound. The major justifications for ultrasound were its noninvasive nature, the ability to exclude more serious disease, and the common finding of cholelithiasis. Of patients who received TPI over the past year, 82% had a positive Carnett sign, 91% had at least a partial initial response, and 45% had a complete initial response. The only nonresponder had a negativeCamett sign. By Fisher's exact test, duration of symptoms, quality of pain, association with physical activity, associationwith GI symptoms, obesity, and previous abdominalsurgery all failed to have a statistically significant relationship to degree of response. Most patients underwent a combination of ultrasound, UGI series, EGD, colonoscopy, abdominal CT scan, and biliary scintigraphy prior to TPI. Rare patients underwent ERCP, cholecystectomy,and exploratory laparotomy. When the prior evaluationsof patientswho receivedTPI were assessed, the average cost of evaluation (excluding initial evaluation and management) was $6727 (using patient charges that are at the 75th percentile of regional charges for diagnostic studies). Conclusions:.Rather than being considered as an initial diagnosis,AWS is frequently treated as a diagnosis of exclusion; .TPI has a high response rate in patients with a positive Carnett sign, and low associatedmorbidity and low expense,warranting its use as a diagnostic tool; ca careful history and physical examination with an appropriate diagnosis of AWS can avoid costly and unnecessary diagnostic studies; and .further prospectivestudy is warranted to better evaluateTPI as both a diagnostic and therapeutic tool.

3228 Visceral Pain Processing In Patients With Painfull Or Painless Functional Bowel Disorders. Mickael Bouin, Pierre Poitras, Michel Boivin, Marie Laganiere,Hosp Saint-Luc du CHUM, Montreal Canada;Ghislain Devroede,Univ de Sherbrooke, Sherbrooke, PQ Canada;Victor Plourde, Hosp Saint-Luc du CHUM, Montreal Canada

BACKGROUND & AIMS: Patients presenting with irritable bowel syndrome fIBS) exhibit abnormal pain tolerance with visceral hypersensibiUty,abnormal referral pain patterns and sensitization to repeated painful stimuli. In the present study, we sought to determine if the altered perception is restricted to patients with IBS or extends also to other functional bowel disorders (FBD) including painless constipation. METHODS:Patients with FBD were identified according to Rome II criteria. Four groups of subjects were studied: normal control subjects (n=lO), painless constipated patients (n=12), and 2 groups of patients with painful FBD including IBS (n = 75) and unspecifiedfunctional bowel disorders (UFBD) (n = 71). All subjects underwent a series of 10 rectal isobaric phasic distensions from 5 to 50 mmHg, randomly distributed, using an electronic barostat. In responseto distensions,subjects reporteddiscomfort and abdominal pain referral if so perceived.The discomfort level was then retested using tracking technique with a second set of distensions (_+ 2 mmHg). Data are expressed in mmHg as mean + SEM. RESULTS: 1) Discomfort thresho/d: Discomfort threshold was lower in patients IBS (29.4 _+ 1) and UFBD (31.5 _+ 1) than in both controls (43.9 _+ 2 mmHg) and painless constipation (41.0 _+ 3 mmHg), (P < 0.01). 2)Aberrant referral pain patterns: 83% IBS, 65% UFBD,42% painless constipation patients and 10% of controls demonstrated aberrant referral pain patterns upon rectal distension. In 18S and UFBDgroups, the patients with aberrant referral pain patterns presentedlower discomfort thresholds than those without referred pain fIBS: 28.4 _+ 1 vs. 34.1 +_ 3, P< 0.05; UFBD: 29.1 + 1 vs. 36.5 -+ 1, P < 0.05). 3) Sensitization during recta/distensions: During the second series of distensions the discomfort thresholds were decreasedas compared to first series of distensions for both groups of patients with abdominal pain fIBS: 26.3 _+ 1 vs. 32.7 _+ 1, P < 0.01; UFBD: 29.9 +_ 1 vs. 34.4 _ 1, P < 0.01). This sensitizationdid not occur in controls or in patients with painless constipation. SUMMARY Low sensory thresholds for pain, abnormal referral pain patterns and sensitization occur only in IBS and UFBD patients while not being observed among painlessconstipatedpatients.CONCLUSIONS:Theseobservationssuggeststhat altered perception is the hallmark of functional bowel disorders associated to abdominal pain.

3231 Alterations in Regional Decreased Cerebral Blood Flow in Patients with Irritable Bowel Syndrome - A PET Imaging Study. Yehuda Ringel, Douglas A. Droseman, Univ of North Carolina, Chapel Hill, NC; Timothy G. Turkington, Duke Univ, Durham, NC; Barbara H. Bradshaw, Univ of North Carolina, Chapel Hill, NC; Robert E. Coleman, Duke Univ, Durham, NC; Stuart Wg Derbyshire, Univ of Pittsburgh Medical Ctr, Pittsburgh, PA; William E. Whitehead, Univ of North Carolina, Chapel Hill, NC

Background:Previousstudies have shown specific alterations in the brain responseto visceral stimulation (i.e., rectal distention) in patients with irritable bowel syndrome fIBS). These studies have reported the differences in increased cerebral blood flow. However,there is no data regarding decreasedCBF in responseto visceral stimulation. Aim: To compare regional decrease in CBF in response to rectal balloon distention in patients with IBS and healthy controls. Methods: We studied 12 dgiff-handed female subjects (6 IBS pts and 6 healthy controls). Positron Emission Tomography (PET) scans using [0-15] water were obtained during rectal balloondistentions and blanktrials. Statisticalparametricmapping (SPM) analysis was performed to identity significant differences in CBF for each distention comparedto the blank tdals. Comparisonsof the changes in the mean regional brain activity for each distention pressure for the IBS group and controls were done by t-test. Results: In responseto 45mmHg rectal distention, there is a significant decrease in CBF in the primary sensory cortex ($1) and posterior temporal (8A 37)/occipital cortex (BA 19) in the control group (left figure) but not in the IBS group (dght figure) (Z=3.33, P
3229 Differential Frontal Deactivations to Somatosensory and Visceral Stimuli in Irritable Bowel Syndrome: A fMRI Study Michael Mclntyre, Uta Frankenstein, Dara Morden, Marshall Pitz, Corinne Leblanc, National Research Council of Canada,Winnipeg Canada;Charles N. 8ernstein, Univ of Manitoba, Winnipeg Canada

Background:It is well known that irritable bowel syndrome fIBS) patientsmanifesta hyperalgesic response to visceral but not to somatosensorystimuli. It is also known that IBS patients manifest different patterns of activation and deactivation to visceral stimuli than do control subjects. One area in which differences have been detected is the cingulo-frontal transition cortex (CFTC).RecentfMRI studies of nociceptionin normals havealso demonstrated deactivation in CFTCto somatosensorystimuli. The present study seeks to document the patterns of blood oxygenationlevel dependentfMRI signal change in IBS patients to somatosensoryand visceral stimuli. Methods: Both whole-brain anatomicaland multi-slice, echo-planarfunctional images were acquired on a 1.5 Tesla GeneralElectric Signa spectrometer. Functional images were obtained while subjects experienced both patterns of visceral stimulation corresponding to subjective experiencesof stool and pain (rectal balloon inflation) alternating with rest and when a noxious somatosensorystimulus (cold-pressor test) alternatedwith a rest condition. Subjects with IBS (n=7) were volunteers from a GI clinic and provided informed consent consistent with the approved NRC ethics protocol. Parametric analysis of the data involved calculation of correlational maps correspondingto the paradigm (p<.001). Maps were filtered so that pixels that were not part of connected sets of 5 activating pixels were excludedas a form of Bonterroni correction. In addition, the pixels that exceededa signal change of 7% were excludedto ensure that detected activations were parenchymal rather than vascular. A non-parameteric analysis was performed to assess the homogeneity of patterns of signal change. Results: IBS subjects demonstrated deactivation in the CFTC in response to coldpressor pain consistent both with the findings from earlier experiments with normals to somatosensory pain and also in normals to noxious visceral stimulations. However, IBS subjects manifestedmuch sparser CFTCdeactivationsto noxious visceral stimulation. Conclusign: There is a differential selective deactivation of the CFTC in conditions of somatic vs visceral noxious stimuli in IBS. This constitutes a functional neuroanatomical difference that may underlie the selective hyperalgesiato visceral stimulation in patients with IBS.

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3232 Is Malabsorption Of Fructose-Sorbitol Really Important In The Irritable Bowel Syndrome fiBS)? Magnus Simren, Agneta Mansson, Dept of Internal Medicine, Gothenburg Sweden; Ulf Bengtsson, Asthma & Allergy Ctr, Gothenburg Sweden; HasseAbrahamsson, Anders F. Kilander, Einar S. Bjomsson, Dept of Internal Medicine, Gothenburg Sweden Background: Within the IBS population 20-30% report gastrointestinalsymptoms after intake of fruits (SimrBn et al Digestion 2001). The importance of fructose-sorbitol malabsorption in IBS remains uncertain. The aim of the present study was to investigateif subjectiveintolerance

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to fruits in IBS can be explained by fructose-sorbitol malabsorption. Methods: 10 patients with IBS according to the Rome I criteria (8 females; age 24-62 years) participated in the study as well as 9 healthy volunteers (7 females; age 24-42 years) without gastrointestinal complaints. All of the IBS patients had previously reported moderate, severe or very severe gastrointestinal symptoms after intake of fruits. The predominant bowel pattern was constipation in 3 of the patients, diarrhea in 2 and alternating diarrhea and constipation in 5. Breath hydrogen was measured after intake of 25g fructose and 5g sorbitol in 300ml water (FS). As control substance 30g glucose + 300ml water (G) was used. The test was performed doubleblind in the patients. The healthy volunteers were tested open and only with froctose-sorbitol. Symptoms during and after the test were analyzed, as well as breath hydrogen for 3 hours after the intake. A sustained rise in breath hydrogen of >20ppm above baselinewere regarded to indicate malabsorption. Results: In the IBS group 9/10 demonstrated a steady rise in breath hydrogen >20ppm after intake of FS compared with 7/9 among the healthy volunteers (ns). The maximal rise in breath hydrogen after FS was 53ppm (5-147) (mean, range) in the patients and 71ppm (4-141) in the healthy volunteers (ns). No rise in breath hydrogen was obseraved after G. A majority of the patients perceived no symptoms at all during the test. No patient perceived severe symptoms during the test. Light - moderate abdominal distension was reported by 4 patients after FS compared with 2 patients after G (ns), light - moderate abdominal pain by 4 patients after FS vs 3 after G (ns) and light - moderate gas problems by 5 patients after FS compared with 4 after G (ns). Four of the healthy volunteers reported mild gas problems after FS, but otherwise no symptoms were present. Conclusion: Malabsorption of fructose-sorbitol is common in IBS as well as among people without gastrointestinal symptoms. IBS patients perceive more symptoms after fructose-sorbitol than healthy controls, but in the IBS patients the symptom paftem was also similar after intake of glucose. The importance of malabsorption of fructose-sorbitol for symptoms in IBS can be questioned. 3233 Lower Vagal Tone Associated with Anxiety Disorders in Womefl with Iwitable Bowel Syndrome Monica E. Jarrett, Robert L. Burr, Kevin C. Cain, Vicky Herbg, Margaret M Heitkemper, Univ of Washington, Seattle, WA There is evidence to suggest that persons with Anxiety disorders (e.g., Panic) have decreased vagal tone, while alterations in persons with Depression are less clear. In addition, persons with anxiety disorders are reported to have faster intestinal transit while those who are depressed may have slower transit. The purpose of this analysis was to compare measures of vagal tone in women with IBS who have a history of symptoms compatible with an anxiety and/or depressive disorder to those with no disorders. Methods. Women, ages 18-48, with medically diagnosed IBS (N = 107) were interviewed using the Diagnostic Interview Schedule (DIS) to determine if they met the criteria for psychiatric disorders based on DSMIII-R criteria (diagnoses included GeneralAnxiety, Panic,Agoraphobia, Phobia, Dysthymla, and Depression). A few weeks later the women wore an ECG Hoiter monitor for 24 hours during the luteal phase of their menstrual cycle. Indicators of cardiac vagal tone were assessed with the Spacelabs FT2000 Hoiter Analyzer (Redmond, WA, USA). For this analysis %RR50 was used as a measure of vagal tone. It is the percentageof normal R-R intervals in 24-hrs that changed in absolute value by more than 50ms from the previous interval. In addition, measures of %RR50 were computed for wake and sleep periods. Results. Women with IBS who had a lifetime history of Panic disorder had lower levels of vagal tone (n = 16, Panic, %RRSO = 7.82 _+ 6.59), as did women with Agoraphobia (n = 26, Agora, %RRSO = 8.61 _+ 6.38), when compared to women with no DIS disorder (n =29, No-DIS, %RRSO = 14.22 +_ 10.54, p = 0.016 and p = 0.018 respectively). Similar differences were found during the wake and sleep periods (p = 0.022-0.002). No difference was seen for women with General Anxiety and Phobic disorders. Women currently experiencing symptoms compatible with a diagnosis of Dysthymia (n = 7) and/or Depression (n = 10) had lower levels of vagal tone (6.91 +__ 4.96) than the women with no DIS disorder (n = 29, No-DIS, %RRSO = 14.22 _+ 10.54, p = .006). Similar differences were found during the wake and sleep periods (p = .003 and p = .006). However, all but 3 of the women with Dystbymia/Deprassion had co-morbid Anxiety disorders. Conclusion. Women with IBS who have symptoms compatible with Panic and/or Agoraphobia disorders appear to have decreased vagal tone both during wake and sleep. Additional exploration is neededto determine if the decreasein vagal tone is associated with differences in motility and/or GI symptom experiences. 3234 Rectal Pain Thresholds are Higher, Not Lower in IBS Patients with History of Sexual/Physical Abuse. Yehuda Ringel, William E. Whitehead, Yuming Jb Hu, Huaoguang Jia, Shrikant I. Bangdiwala, Douglas A. Drossman, Univ of North Carolina, Chapel Hill, NC Background: Reduced pain thresholds for rectal distention has been proposed as a possible mechanism in the pathophysiology of irritable bowel syndrome (IBS). The prevalence of sexual/physical abuse in referred IBS patients is high and is associated with greater pain reporting, poorer health status, and poorer outcome. It is unclear whether greater pain reporting in this group relates to CNS or visceral influences. Aim: Our aim was to determine whether the increased rectal pain sensitivity in IBS patients is influenced by prior history of sexual/ physical abuse. Methods: One hundred ninety six female patients with IBS and/or chronic functional abdominal pain were studied for rectal pain sensitivity by electronic barostat. Pain thresholds were determined by ascending method of limit (AML) (i.e., pressure at first report of pain) and by tracking method (i.e., mean pressure for 20 unpredictable distentions in which subjects reported painful sensation of at least moderate intensity). Abuse history was assessed by standardized questionnaire. Thereafter, these thresholds were compared between 55 patients with a history of severe sexual/physical abuse (i.e., rape, often hit or life threatened) and 50 patients with no abuse history. Results: Pain thresholds determined by bath methods (i.e., AML and tracking) for severe-abusedand non-abused patients are shown in the figure. Conclusions: Severesexual/physical abuse is associatedwith higher, not lower pain thresholds for rectal distention in IBS patients. This suggests that the greater pain reporting and poorer health status in IBS patients with abuse history may relate to other factors (e.g. alterations

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3235 Responses ta Postprandial Mental Strut in Women with IBS Sigrid Elsenbrach, Unlv Clin of Essen, Dept of Medical Psychology, Essen Germany; William R. Lovallo, VA Medical Ctr, Oklahoma City, OK; William C. Orr, Lynn Institute for Heaithcare Research, Oklahoma City, OK BACKGROUND:IBS pathophysiology may involve abnormal descending mechanisms, including altered autonomic and hypothalamic-pituitary-adrenal axis responses.The role of psychological factors in autonomic and endocrine dysfunction found in response to visceral stimuli in IBS remains unresolved. If descending mechanisms modulate responses to visceral stimuli, this would be particularly prominent during stress. Therefore, the goal was to investigate whether postprandial stress modulates the affective + symptomatic and the autonomic + cortisol responses to food ingestion in IBS patients. METHODS:24 women with IBS and 20 controls completed the 2-day protocol, which included a standard meal followed by rest or a stressor. The stressorwas a reaction time task based on a variant of the Stroop Color Test. Heart rate variability, cortisol, affective, and symptomatic responses were measured. RESULTS: IBS patients showed increased negative affect after food alone (p<.01). In response to stress, patients showed a further increase in negative affect, which was significantly greater than the control group s reaction (p<.05). Despite these group differences in the emotional stress response, IBS patients cognitive appraisal of the task s characteristics (i.e., aversiveness, stresstullness, difficulty, self-confidence) was not different from controls. Gastrointestinal (GI) symptoms increased significantly after the meal on the rest day in patients but not controls (p<.O01). No further symptom increase was observed on the stress day. Although both patients and controls showed significant increases in heart rate and changes in the low frequency to high frequency power band ratio in response to the stressor (within-group comparisons, all p<.05), there were no between-group differences. There was a significant postprandial corbsol increase on the control day in IBS patients (p<.05), but no overall cortisol responseto the stressor in either group. CONCLUSION:(1) IBS patients are emotionally more responsive to visceral (food) and nonvisceral stimuli (stress). However, these affectlve responses are not related to altered autonomic or cortisol responses. (2) IBS patients cannot be differentiated from controls based on the pattern of changes in sympathetic activation following stress. (3) The lack of symptomatic stress response may have been due to the fact that responses to the meal alone overshadowed any reaction to the stressor. These findings further supports the importance of visceral over non-visceral stimuli in IBS.

The Hospital Anxiety and Depression Scale® (FIAOS) Provides a Practical, Simple and Functional Patient-adminicterad Test for Anxiety and Depression in a Clinical GI Practice. Mary Elizabeth Glass, North Cent Univ, Prescott, AZ; V. Alin Botoman, Cleveland Clin Rorida, Ft Lauderdale, FL; Richard Jones, North Cent Univ, Prescott, AZ; Sue Bruno, Lyne Labpe, Irys Caristo, Cleveland Clin Florida, R Lauderdale, FL Introduction: Anxiety and depression are common in GI patients. Quantitative means for diagnosing depression or anxiety, such as the MMPI are laborious and require specialized training. Referrals to a therapist may be impractical,expensive,or resisted by the patient. The Beck Anxiety Inventory®(BAI) and Beck Depression Inventory~ (BDI)are widely available, but require 2 separate 21 item questionnaires. The Hospital Anxiety and Depression Scale® (HADS) is a short simple 14 item self-administered test, previously validated in UK hospital pts. This test has not been validated in GI US outptients. We were also interested in the ability of a clinical gastroenterologist(GI) to diagnose anxiety/depression via brief office mental status examination (MSE). Materials and Methods: 50 patients referred to a busy GI practice, focused on functional GI disorders, were enrolled through a brief invitation letter prior to visit. Interested study participants were given informed consent and standardized instructions then took the BAI, BDI and HADS tests in random order just prior to clinic visit. All patients were seen by one physician (VA6), who was blinded to the test results, and who separately recorded a brief MSE and psych, diagnosis. All forms were analyzed by one investigator (MEG) who had no contact with the study patients. Statistical analysis was carried out using linear regression (null hypothesis p=O.SO), scatter plot analysis, and the Fisher Z test for normalcy using statistical software (MS Excel 97®;and SPSS~). The anxiety and depression parts of the HADS scale were compared with their counterpart Beckscales. Correlativestatistics were also carded out with the physician MSE.Resuits: There was a high degree of correlation (r=0.85) between the BDI and HADS Depression (p