IBS Constipation Research Articles

Acacia fiber or probiotic supplements to relieve gastrointestinal complaints in patients with constipation-predominant IBS: a 4-week randomized double-blinded placebo-controlled intervention trial

PurposeTo date, no adequate treatment for irritable bowel syndrome with predominant constipation complaints (IBS-C) is available. Fibers with prebiotic properties and probiotic compounds have shown promise in relieving IBS-C-related complaints. We aimed to determine the effects of a 4-week intervention with either an Acacia fiber (AF) with prebiotic properties or a probiotic Bifidobacterium Lactis (BLa80) supplement, compared to a control supplement, on stool pattern, IBS symptoms and Quality of Life (QoL), in IBS-C individuals.MethodsA parallel, double-blind, randomized controlled trial involving 180 subjects meeting the ROME IV criteria for IBS-C was conducted. Following a 4-week observation period, subjects received either AF (10 g), Probiotic BLa80 (4 g; 2 × 1011 CFU/g) or a maltodextrin placebo (10 g) daily for 4 weeks. Subjects reported daily information on stool pattern and gastrointestinal complaints. Before and after each 4-week period, questionnaires on symptom severity, constipation symptoms, anxiety and depression and QoL were completed. Stool mass was measured for 5-days before and after the intervention.ResultsStool frequency significantly improved in the AF and Probiotic BLa80 groups compared to placebo (P < 0.001, P = 0.02, respectively). Probiotic BLa80 showed a significant reduction in IBS symptom severity (P = 0.03), for AF a trend towards decreased constipation symptoms (PAC-SYM, P = 0.10) was observed. No significant changes in stool consistency, stool mass or QoL measures were observed between the AF and Probiotic BLa80 compared to placebo.ConclusionDaily dietary supplementation with Acacia fiber and probiotic supplements might help IBS-C patients by relieving IBS-related complaints compared to a placebo supplement.Registration number of clinical trialThe trial is registered at ClinicalTrials.gov: NCT04798417: Study Details | Nutrition to Relieve IBS Constipation | ClinicalTrials.gov.

Gut microbiome signatures reflect different subtypes of irritable bowel syndrome

ABSTRACT Irritable bowel syndrome (IBS) is a heterogeneous condition with multifactorial pathogenesis. We studied deeply phenotyped individuals with microbiota sequencing enrolled in the American Gut Project. The IBS subjects were matched by age, gender, body mass index, geography, and dietary patterns with non-IBS controls. A total of 942 subjects with IBS-Diarrhea (IBS-D), IBS-Constipation (IBS-C), unclassified IBS (IBS-U), and 942 non-IBS controls were included. We compared taxonomic and functional composition of gut microbiota based on 16S sequencing data and linked them with clinical characteristics and dietary factors. Subjects with IBS-D or IBS-U but not IBS-C showed significantly reduced bacterial diversity (Shannon; p < .01). Distinct bacterial signatures were associated with different IBS subtypes, and the related functional changes were related to IBS pathogenesis, such as the increased hydrogen sulfide production pathway in IBS-D and the increased palmitoleate biosynthesis pathway in IBS-C. IBS subjects with depression showed lower abundance of Bifidobacterium, Sutterella, Butyricimonas and higher abundance of Proteus than those without depression. The relative abundance of microbial short-chain fatty acid production pathways was significantly lower in IBS patients with depression than those without depression in all three subtypes. Female, younger age in IBS-D, and older age in IBS-C were associated with more severe microbiota dysbiosis, and distinct dietary factors had significant effects on the gut microbiota in different IBS subtypes. Our analysis identified the compositional uniqueness of gut microbiota in different IBS subtypes. Distinct associations of the gut microbiota with depression in IBS provide insights into shared pathways in disease pathogenesis. These findings highlight the importance of personalized gut microbiome modulation approaches in different subtypes for optimal therapeutic effects.

Efficacy of whole system ayurveda protocol in irritable bowel syndrome – A Randomized controlled clinical trial

BackgroundIrritable bowel syndrome (IBS) is one of the clinically challenging disorders. It has a significant effect on health, cost and quality of life. Ayurveda management through whole system approach in IBS is explored. ObjectiveTo evaluate the efficacy of whole system Ayurveda approach in IBS. MethodsThe present trial is a randomized controlled parallel group study. 48 patients diagnosed as IBS (Rome IV Criteria) between the age group of 20–60 yrs were recruited in the study. Patients were randomly divided into 2 groups. KC group intervened with Kalingadi Churna 3 gm twice a day, before food with buttermilk. WS group intervened with whole system ayurveda protocol (WSAP). Duration of intervention was 60 days with follow up on every 15th day. Assessments were through various clinical measures like IBS Symptom Severity Score (IBS-SSS), IBS Adequate Relief (IBS-AR), Gastrointestinal symptom rating scale (GSRS), IBS-VAS, Complete Spontaneous Bowel Movements (CSBMs), Bristol Stool Form (BSF), Hamilton Anxiety Rating Scale (HARS), Hamilton Depression Rating Scale (HDRS), IBS quality of life (IBS-QoL) at every follow up. Hemoglobin, Erythrocyte sedimentation rate and stool examination was conducted at pre and post study. ResultsStudy showed that WS group had significant improvement compared to KC group in IBS-SSS, IBS-AR, IBS-VAS, CSBM, BSF-Diarrhea and BSF-Constipation. Both groups were comparable in GSRS, HARS, HDRS and IBS-QOL. Blood and stool parameters assessments showed comparable improvements in both the groups. Within group significant improvements in all the clinical assessment scales were observed in both the groups. ConclusionWSAP was effective in management of IBS (IBS constipation and IBS diarrhea). Improvements were observed in abdominal pain, stool frequency, consistency and adequate relief.

The fragility of randomized placebo-controlled trials for irritable bowel syndrome.

The fragility index (FI) represents the number of participants whose status in a trial would have to change from a non-event (not experiencing the primary endpoint) to an event (experiencing the primary endpoint) in order to turn a statistically significant result into a non-significant result. We sought to evaluate the fragility indices of irritable bowel syndrome [IBS-mixed (IBS-M), IBS-constipation (IBS-C), & IBS-diarrhea (IBS-D)] trials. Irritable bowel syndrome trials published in high-impact journals were identified from Medline. Trials had to be in adults, randomized, parallel-armed, with at least one statistically significant binary outcome, and an achieved primary endpoint of therapeutic efficacy. FI and correlation coefficients were calculated, and regression modeling used to identify predictors of a high FI. Twelve trials were analyzed with a median FI of 6 (range: 0-38). Median sample size in all trials was 366 (range: 44-856). Trial publication year (p=0.71), journal impact factor (p=0.52), duration of study (p=0.12), and number need to treat [NNT] (p=0.29) were not predictive of a high FI. While a lower p-value correlated with a higher FI (p=0.039), no correlation was noted between FI and impact factor (R=-0.20, p=0.52), trial publication year (R=0.12, p=0.71), duration of trial (R=-0.46, p=0.13), NNT (R=-0.34, p=0.29), and sample size (R=0.23, p=0.5). The highest FI was in a Ramosetron trial (FI=30) for IBS-D. A median of six participants is needed to nullify results in the included IBS trials suggesting how easily statistical significance based on a threshold p-value may be overturned.

Differential mRNA Expression in Ileal Mucosal Biopsies of Patients With Diarrhea- or Constipation-Predominant Irritable Bowel Syndrome.

INTRODUCTION:Previous studies in patients with irritable bowel syndrome (IBS) showed immune activation, secretion, and barrier dysfunction in duodenal, jejunal, or colorectal mucosa. This study aimed to measure ileal mucosal expression of genes and proteins associated with mucosal functions.METHODS:We measured by reverse transcription polymerase chain reaction messenger RNA (mRNA) expression of 78 genes (reflecting tight junction proteins, chemokines, innate immunity, ion channels, and transmitters) and 5 proteins (barrier, bile acid receptor, and ion exchanger) in terminal ileal mucosa from 11 patients with IBS-diarrhea (IBS-D), 17 patients with IBS-constipation (IBS-C), and 14 healthy controls. Fold changes in mRNA were calculated using 2(−Δ, ΔCT) formula. Group differences were measured using analysis of variance. Protein ratios relative to healthy controls were based on Western blot analysis. Nominal P values (P < 0.05) are reported.RESULTS:In ileal mucosal biopsies, significant differences of mRNA expression in IBS-D relative to IBS-C were upregulation of barrier proteins (TJP1, FN1, CLDN1, and CLDN12), repair function (TFF1), and cellular functions. In ileal mucosal biopsies, mRNA expression in IBS-C relative to healthy controls was reduced GPBAR1 receptor, myosin light chain kinase (MYLK in barrier function), and innate immunity (TLR3), but increased mRNA expression of cadherin cell adhesion mechanisms (CTNNB1) and transport genes SLC9A1 (Na-H exchanger [NHE1]) and INADL (indirect effect on ion transport).DISCUSSION:These data support a role of ileal mucosal dysfunction in IBS, including barrier dysfunction in IBS-D and alterations in absorption/secretion mechanisms in IBS-C.

Blastocystis ST-1 is associated with Irritable Bowel Syndrome-diarrhoea (IBS-D) in Indonesian adolescences

ObjectiveIBS is a functional gastrointestinal disorder and commonly presents in children and adolescences, presented as diarrhoea, constipation or mixed type. Blastocystis is a common intestinal protozoa found worldwide, which pathogenicity is still controversial. This study aimed to identify the risk factors of IBS, the association between IBS types with Blastocystis subtypes and analyse Blastocystis pathogenicity. DesignA comparative cross-sectional study was conducted among senior high school students. Rome III Criteria for IBS diagnosis, questionnaires on the risk factors of IBS and types of IBS were recorded. Students were further selected and classified into IBS and non-IBS groups to analyse the association between IBS, IBS types with Blastocystis infection and its subtypes. Direct microscopic stool examination to identify single Blastocystis infection was performed, followed by culture in Jones' medium, PCR, sequencing of 18S rRNA and phylogenetic analysis to determine Blastocystis subtype. Data was analysed using SPSS v22.0 and P value <0.05 was considered statistically significant (95% confidence intervals). ResultsIBS was found in 30.2% of 454 students, consisted of 33.3% IBS Diarrhoea, 27.7% IBS Mixed, 27.7% IBS Unclassified and 11.1% IBS Constipation. Major risk factors to IBS consisted of family history of recurrent abdominal pain, abuse, bullying and female gender in respective order (OR 3.6–2.1). Blastocystis ST-1 was significantly associated to IBS-D with 2.9 times risk factor. ConclusionsBlastocystis infection is a risk factor to develop IBS-D type in adolescence; Blastocystis ST-1 can be regarded as a pathogenic subtype.

Aquaporin Expression in Colonic Mucosal Biopsies From Irritable Bowel Syndrome With Diarrhea.

INTRODUCTION:Aquaporin (AQP) channels are involved in regulating fluid homeostasis in the colon. Several AQP channels were detected in human colon epithelial cells. In a previous study, rats fed 1% (wt/wt) sodium cholate had increased AQP3, 7, and 8 levels, suggesting AQP involvement in bile acid diarrhea (BAD). Our aim was to compare AQP expressions in rectosigmoid mucosal (RSM) biopsies from patients with irritable bowel syndrome–diarrhea (IBS-D) (divided into those with normal or high fecal BA excretion) and in patients with IBS-constipation (IBS-C) compared with healthy controls.METHODS:In RSM biopsies from 44 patients with IBS-D (with normal (<) or high (>2,337 μmol/48 hours (BAD)) fecal BA excretion), 10 patients with IBS-C, and 17 healthy controls, we measured expressions of AQP1, 3, 7, and 8, with RT-PCR (housekeeper gene GAPDH). We analyzed RNA for expression by RT2-PCR assays, with expression calculated using 2−ΔΔCT-based fold-change. Comparisons of IBS groups were corrected for false detection rate (Bonferroni correction for 12 comparisons; P < 0.0042). AQP protein measurements on biopsies from 3 healthy controls, 3 patients with IBS-D, and 3 patients with BAD were performed by western blots (GAPDH housekeeping protein).RESULTS:In RSM from patients with IBS-D (but not IBS-C), mRNA expression of AQP3 was decreased, and AQP7 and 8 were increased relative to controls. Fold differences were not different in IBS-D with or without BAD. Western blots confirmed increased expression of AQP7 and 8 and decreased AQP3 proteins in biopsies from patients with IBS-D compared with controls.CONCLUSIONS:Increased AQP7 and 8 and decreased AQP3 expressions in RSM suggest that further studies on AQPs' potential role in the pathophysiology of diarrhea in IBS-D are warranted.

Fecograph: A graphical representation of daily stool forms to subtype irritable bowel syndrome in office practice.

Background and AimInterpreting stool form diaries for subtyping patients with the irritable bowel syndrome (IBS) is cumbersome; a picture showing a trend would be easier to interpret.MethodsFifty‐one consecutive adults with IBS (median age 35.5 years; 47 men), diagnosed using the Rome III criteria, were given a picture of the Bristol stool form scale (BSFS) and asked to record their stool frequency and form for 7 days. The numbers were plotted by a technician as dots on a chart. On the y axis, BSFS category 4 was marked as 0, harder stools as +1 to +3, and softer stools as −1 to −3; each bowel movement was represented on the x axis. A line graph was plotted by connecting the dots. Each “fecograph” was then given for visual interpretation to three gastroenterologists (observers). When most readings appeared to be 0, +1, or −1, it was to be reported as normal; most above +1 as IBS‐constipation (IBS‐C); most below −1 as IBS‐diarrhea (IBS‐D); and readings crossing 1 on either side as IBS‐mixed (IBS‐M). If no clear trend was noted, it was IBS‐unclassified (IBS‐U). Each observer reported all graphs in different orders twice, at 1‐month intervals; thus, 306 reports were available. Interclass correlation coefficient (ICC) was calculated.ResultsEighteen patients had IBS‐C, 13 IBS‐D, 4 IBS‐M, and 16 IBS‐U. The 51 fecographs were reported in mean 20 min 36 s. ICC for intra‐ and interobserver reliability was 0.62 (0.50–0.73).ConclusionThe fecograph is a reliable and easy‐to‐use tool to subtype patients with IBS.

Diagnostic value of neutrophil to lymphocyte ratio, platelet to lymphocyte ratio and mean thrombocyte volume in irritable bowel syndrome-constipation according to rome IV criteria

Aim: Structural and biochemical reagents that could help diagnose irritable bowel syndrome (IBS) are still lacking. Moreover, use of certain diagnosis criteria in the diagnosis of the disease decreases the need for making over-diagnostic tests in order to rule out other diseases. Rome IV criteria include new parameters for the diagnosis of IBS. Our objective in this study is to research the diagnostic value of neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR) and mean platelet volume (MPV) count in IBS-Constipation (IBS-C).Material and Methods: Data of the cases among patients who applied to general surgery polyclinics of Ordu University Medical Faculty who were diagnosed with IBS and have Rome IV IBS-C diagnosis criteria. Healthy volunteers were selected from adult healthy patients who applied to general surgery policlinics of our hospital for general health check purposes. The age, sex, WBC (white blood cell), NLR, PLR, MPV values of the cases were analyzed. Results:Average age of IBS-C group was 39.47±9.97 (min 19-max 57). Average age of the control group was 40.16±11.50 (min 18-max 59). Out of 78 IBS-C group patients, 48 (61.5%) were women and 30 (38.5%) were men. Of 82 patients 54 (65.9%) were women, 28 (%34.1) were men. Average age of the patients was 39.83±10.75 (min 18-max 59). A significant result was obtained for NLR when control group was compared with IBS-C group (p=0.01). No significant difference was determined between two groups for MPV, PLR (p>0.05). Cut-off value of NLR was calculated as 1.895, and the sensitivity in IBS diagnosis was calculated as 51.3%, and the specificity was calculated as 59.8%. Conclusion: We have determined significant results with NLR, which is an inflammatory reagent, in IBS-C according to Rome IV Criteria. However, NLR has low sensitivity and specificity for IBS-C diagnosis from the other causes of constipation. We are of the opinion that inflammatory reagents such as NLR, PLR, MPV are not useful in the diagnosis of this disease. We consider that our study will shed a light on future studies with larger research populations.

Irritable bowel syndrome subtypes: Clinical and psychological features, body mass index and comorbidities.

Irritable bowel syndrome (IBS) is classified into subtypes according to bowel habit. To investigate whether there are differences in clinical features, comorbidities, anxiety, depression and body mass index (BMI) among IBS subtypes. The study group included 113 consecutive patients (mean age: 48 ± 11 years; females: 94) with the diagnosis of IBS. All of them answered a structured questionnaire for demographic and clinical data and underwent upper endoscopy. Anxiety and depression were assessed by the Hospital Anxiety and Depression scale (HAD). The distribution of subtypes was: IBS-diarrhea (IBS-D), 46%; IBS-constipation (IBS-C), 32%, and mixed IBS (IBS-M), 22%. IBS overlap with gastroesophageal reflux disease (GERD), functional dyspepsia, chronic headache and fibromyalgia occurred in 65.5%, 48.7%, 40.7% and 22.1% of patients, respectively. Anxiety and/or depression were found in 81.5%. Comparisons among subgroups showed that bloating was significantly associated with IBS-M compared to IBS-D (odds ratio-OR-5.6). Straining was more likely to be reported by IBS-M (OR 15.3) and IBS-C (OR 12.0) compared to IBS-D patients, while urgency was associated with both IBS-M (OR 19.7) and IBS-D (OR 14.2) compared to IBS-C. In addition, IBS-M patients were more likely to present GERD than IBS-D (OR 6.7) and higher scores for anxiety than IBS-C patients (OR 1.2). BMI values did not differ between IBS-D and IBS-C. IBS-M is characterized by symptoms frequently reported by both IBS-C (straining) and IBS-D (urgency), higher levels of anxiety, and high prevalence of comorbidities. These features should be considered in the clinical management of this subgroup.

Patients Sith Diarrhea-Predominant Irritable Bowel Syndrome Have Lower Disease-Specific Quality of Life Than Constipation-Predominant Irritable Bowel Syndrome

Introduction: Irritable bowel syndrome (IBS) specific quality of life (IBS-QOL) questionnaire is the most extensively-validated health-related QOL-specific instrument for IBS. There is a paucity of data on the effect of IBS-subtype on the IBS-QOL. We carried out a prospective, cross-sectional study of IBS patients visiting our functional gastroenterology disorder clinic at a quaternary care center to determine the effect of IBS subtype on the overall IBS-QOL and its various subscales from 2011 to 2013. Methods: IBS and IBS subtype were diagnosed using a Rome-III questionnaire and the IBS-QOL was administered to all patients once they were diagnosed with IBS. The overall IBS and the individual subscale scores were calculated as per the IBS-QOL scoring manual and were scored on a range of 0-100 with higher score suggestive of better QOL. Similar scores on a range of 1-100 were reported for all the 8 subscales - body image, food avoidance, interference with activity, relationship, social reaction, sexual, health worry, and dysphoria. Results: Of 474 patients screened over the last 2 years, 215 met Rome III criteria for IBS. IBS-mixed type (IBS-M) was the most common subtype (109 patients, 50.7%) followed by IBS-diarrhea (IBS-D) (49 patients, 22.8%), IBS-constipation (IBS-C) (46 patients, 21.4%), and IBS-unspecified (IBS-U) (11 patients, 5.1%). Patients with IBS-D had lowest IBS-QOL (59.1; 95% CI, 52.7-65.5) followed by IBS-M (61.9; 95% CI, 56.8-67), IBS-C (70.9; 95% CI, 63-78.8) and IBS-U (74.8; 95% CI, 58.4-91.3). Overall IBS-QOL of patients with IBS-D was significantly lower than patients with IBS-C (p=0.01) and IBS-U (p=0.04). Patients with IBS-D scored significantly lower than IBS-C on following domains - food avoidance (37.8; 95% CI, 28.4-47.1 vs. 54.5; 95% CI, 43.1-65.8, p=0.02), interference with activity (58.5; 95% CI, 51.4-65.6 vs. 79.5; 95% CI, 72.4-86.6, p<0.001), and relationship (73.1; 95% CI, 66.6-79.6 vs. 82.9; 95% CI, 76.5-89.4, p=0.03). Conclusion: Patients with IBS-D have lower disease-specific QOL than IBS-C patients. Clinicians should consider paying special attention to food avoidance, effects on daily activities and problems with relationships in IBS-D patients as these domains significantly affect QOL. Interventions targeted towards these QOL domains could provide the greatest impact this subset of IBS patients. Disclosure - Dr. Kuo: Consultant Furiex, Biogen, Theravance, Genova, Given Imaging, Research Support: GSK, Given, Furiex.

Validating biomarkers of treatable mechanisms in irritable bowel syndrome.

A valid biomarker is 'an indicator of normal biologic or pathogenic processes, or pharmacological responses to a therapeutic intervention'. There is no validated biomarker for irritable bowel syndrome (IBS). The aim of the study was to assess ability of three quantitative traits to identify treatable processes to discriminate between IBS-diarrhea (IBS-D) patients, IBS-constipation (IBS-C) patients and healthy volunteers (HV). In 30 HV, 30 IBS-C patients and 64 IBS-D patients, we characterized bowel symptoms and quantitated pathophysiological mechanisms: bile acid (BA) synthesis (serum C4 and FGF19), fecal BA and fat, colonic transit (CT), and intestinal permeability (IP). We used multiple logistic regression and receiver-operating characteristic (ROCAUC ) to appraise three factors (fecal BA, CT, and IP) individually and in combination to identify discriminant targets for treatment in IBS. There were significant associations between the three subgroups and symptoms reflecting bowel function and the quantitative traits. There were significant associations between fecal BA and CT at 48 h (r = 0.43; p < 0.001) and between fecal BA and IP (r = 0.23; p = 0.015). Individually, fecal BA and CT48 (but not IP) were significant independent predictors for distinguishing HV from IBS. In combination, they discriminated HV from IBS-D patients (ROCAUC 0.70), HV from IBS-C patients (ROCAUC 0.73), and IBS-C patients from IBS-D patients (ROCAUC 0.86). Colonic transit and fecal BA excretion together discriminate between healthy volunteers and IBS-C patients or IBS-D patients, or between the IBS subgroups with 75-90% specificity at 60% sensitivity. Colonic transit and fecal BA individually and together constitute useful biomarkers to identify treatable mechanisms in IBS and to differentiate subgroups of IBS.

Association of bile acid receptor TGR5 variation and transit in health and lower functional gastrointestinal disorders

The membrane bound bile acid (BA) receptor, TGR5, is located on myenteric, cholinergic and nitrergic neurons in colon and proximal small intestine. Our aim was to assess the association of genetic variation in TGR5 and small bowel transit (SBT) and colonic transit. In 230 healthy controls and 414 patients with lower functional GI disorders [FGID: irritable bowel syndrome (IBS)-alternators (Alt) 84, IBS-constipation (IBS-C) 157, IBS-diarrhea (IBS-D) 173], we tested the association between TGR5 SNP rs11554825 (minor allele frequency 41%) with symptom phenotype (total cohort) and intermediate phenotype (SBT or colonic transit by radioscintigraphy) which was available in 213 people in this cohort. The association with symptom phenotype was assessed using logistic regression, while the association with colonic filling at 6 h (CF6), and colonic transit [geometric center (GC) at 24 h] was assessed using ancova, in each instance assuming a dominant genetic model. There was no significant association with symptom phenotype. We observed a potential association of SNP rs11554825 with overall transit: CF6 (P = 0.061) and GC24 (P = 0.083). The association of the SNP with CF6 in the IBS-D subgroup (P = 0.017) indicated the TC/CC subgroup had an average 50% faster SBT compared with the TT subgroup. In IBS-D patients, GC24 was not significantly associated with rs11554825 (TC/CC vs TT). Variation in TGR5 may contribute to altered SBT and colonic transit in lower FGID. Further studies are required to characterize the potential role of BA receptor, TGR5, in the mechanism and treatment of bowel dysfunction in lower FGID.

Association of TNFSF15 polymorphism with irritable bowel syndrome

BackgroundIrritable bowel syndrome (IBS) is the most common gastrointestinal disorder, affecting more than 10% of the general population worldwide. Although a genetic component is suspected, unambiguous susceptibility genes have so...

Symptom criteria for constipation subtypes in a U.S. national epidemiological study of constipation

Introduction. Existing criteria for constipation are based on expert clinical consensus. We conducted a large US national study to evaluate the validity of these symptom-based clinical consensus criteria for functional constipation, IBS constipation and outlet delay. Methods. We contacted a nationwide sample of households by telephone. Among eligible individuals contacted, 69% agreed to participate. A total of 10,018 interviews were completed. Individuals were asked detailed questions about 15 constipation-related symptoms. Interview data were used to identify individuals who met a priori symptom criteria for functional constipation (e.g., Rome criteria), IBS (e.g., Rome), and outlet delay (e.g., Talley etal). Principal components factor analysis was used to determine if the 15 different symptom variables clustered in a manner consistent with a priori criteria. Results. Three factors (i.e., symptom clusters) emerged that overlapped to some degree but were distinct from a priori definitions for functional constipation, IBS, and outlet delay. A fourth factor emerged for self-reported constipation. While number of bowel movements per week (BM/week) is often used to define constipation, it was not strongly correlated with (i.e., did not load with) any of the factors. In contrast, number of completed (i.e., a sense of complete emptying) BM/week was an important item strongly correlated with functional constipation. The factors and loading or weight for each item (i.e., correlation of the item with the factor and visa versa) are summarized below. For self-reported constipation the items (and weights) were self report (0.74), laxatives (0.48), straining (-0.59) and hard stools (-0.67).

A large US national epidemiological study of constipation

Introduction: Published estimates of the prevalence of constipation vary widely, due, in part, to variation in case definitions used and survey methods. The study was conducted to obtain detailed data on a broad spectrum of lower GI symptoms in the US population. The objective of this study was to estimate the prevalence of constipation and clinical subtypes and determine if subtypes differed by sociodemographic factors. Methods: Between June, 1997 and September, 1997, 10,018 individuals 18 years of age and older completed a telephone interview about bowel habits and constipation-related symptoms. A total of 69% of the eligible individuals who were contacted agreed to participate. The recall period for reporting symptoms was the 3 months before the interview. Interview data on 15 constipation-related symptoms were used to identify individuals who met a priori symptom criteria for functional constipation (e.g., Rome criteria), IBS constipation (e.g., Rome), outlet obstruction (e.g., Talley et al), and selfreported constipation (i.e., self-reported and not in one of the other 3 groups). Results: The prevalence of constipation for all subtypes combined was estimated at 28%. By subtype, the prevalence was 8% for functional constipation (FC), 9% for IBS constipation (IBS), 6% for outlet obstruction (OD), and 5% for self-reported constipation (subjects who did not meet criteria for the other subtypes). Prevalence of constipation subtypes differed in their association with sociodemographic factors. In particular, the female to male (F/M) gender ratio was lowest for FC (F/M=0.86) and elevated for OD (F/M=I.5) and IBS (F/M=2.0). Prevalence decreased with increasing age, especially for FC and IBS. Prevalence of FC appears to increase with increasing education. OD was more common among non-Whites compared to Whites. Forty percent of individuals with constipation reported having the condition for 5 years or more. Conclusions: Data from this study indicate that constipation is a common chronic condition affecting approximately 55 million people in the US. Evidence from this study indicates that constipation subtypes vary to some degree by sociodemographic factors. Finally, these data suggest that both FC and OD may have been substantially underestimated in previous studies. This study was supported by Janssen Research Foundation, Titusville, NJ