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Rifaximin is FDA-approved for treatment of irritable bowel syndrome with diarrhea (IBS-D), but poor solubility may limit its efficacy against microbes in the mucus layer, e.g. Escherichia coli. Here we evaluate adding the mucolytic N-acetylcysteine (NAC) to improve rifaximin efficacy. In a resazurin checkerboard assay, combining rifaximin with NAC had significant synergistic effects in reducing E. coli levels. The optimal rifaximin + NAC combination was then tested in a validated rat model of IBS-D (induced by cytolethal distending toxin [CdtB] inoculation). Rats were inoculated with vehicle and treated with placebo (Control-PBS) or rifaximin + NAC (Control-Rif + NAC, safety), or inoculated with CdtB and treated with placebo (CdtB-PBS), rifaximin (CdtB-Rifaximin), or rifaximin + NAC (CdtB-Rif + NAC) for 10 days. CdtB-inoculated rats (CdtB-PBS) developed wide variability in stool consistency (P = 0.0014) vs. controls (Control-PBS). Stool variability normalized in rats treated with rifaximin + NAC (CdtB-Rif + NAC) but not rifaximin alone (CdtB-Rifaximin). Small bowel bacterial levels were elevated in CdtB-PBS rats but normalized in CdtB-Rif + NAC but not CdtB-Rifaximin rats. E. coli and Desulfovibrio spp levels (each associated with different IBS-D microtypes) were also elevated in CdtB-inoculated (CdtB-PBS) but normalized in CdtB-Rif + NAC rats. Cytokine levels normalized only in CdtB-Rif + NAC rats, in a manner predicted to be associated with reduced diarrhea driven by reduced E. coli. These findings suggest that combining rifaximin with NAC may improve the percentage of IBS-D patients responding to treatment., (© 2024. The Author(s).)

Irritable bowel syndrome (IBS) is a highly prevalent, chronic disorder that significantly reduces patients' quality of life. Advances in diagnostic testing and in therapeutic options for patients with IBS led to the development of this first-ever American College of Gastroenterology clinical guideline for the management of IBS using Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Twenty-five clinically important questions were assessed after a comprehensive literature search; 9 questions focused on diagnostic testing; 16 questions focused on therapeutic options. Consensus was obtained using a modified Delphi approach, and based on GRADE methodology, we endorse the following: We suggest that a positive diagnostic strategy as compared to a diagnostic strategy of exclusion be used to improve time to initiating appropriate therapy. We suggest that serologic testing be performed to rule out celiac disease in patients with IBS and diarrhea symptoms. We suggest that fecal calprotectin be checked in patients with suspected IBS and diarrhea symptoms to rule out inflammatory bowel disease. We recommend a limited trial of a low fermentable oligosaccharides, disacchardies, monosaccharides, polyols (FODMAP) diet in patients with IBS to improve global symptoms. We recommend the use of chloride channel activators and guanylate cyclase activators to treat global IBS with constipation symptoms. We recommend the use of rifaximin to treat global IBS with diarrhea symptoms. We suggest that gut-directed psychotherapy be used to treat global IBS symptoms. Additional statements and information regarding diagnostic strategies, specific drugs, doses, and duration of therapy can be found in the guideline., (Copyright © 2020 by The American College of Gastroenterology.)

Introduction: Abdominal pain is the principal symptom of irritable bowel syndrome (IBS). This analysis examined abdominal pain response in adults with IBS with diarrhea (IBS-D) receiving the nonsystemic antibiotic rifaximin., Methods: In the Targeted Nonsystemic Antibiotic Rifaximin Gut-Selective Evaluation of Treatment for IBS-D 3 trial, adults with IBS-D received open-label rifaximin 550 mg 3 times daily for 2 weeks, followed by the 4-week post-treatment phase assessing abdominal pain and stool consistency response. Responders were followed for up to 18 additional weeks; patients with recurrence were randomly assigned to receive two 2-week courses of double-blind rifaximin 550 mg 3 times daily or placebo, separated by 10 weeks. Analyses evaluated mean weekly improvements from baseline (e.g., ≥30%, ≥40%, and ≥50%) in abdominal pain during the 4-week post-repeat-treatment phases., Results: Of the 2,438 evaluable patients, 1,384 (56.8%) had abdominal pain response to open-label rifaximin (≥30% improvement from baseline in the mean weekly abdominal pain score during ≥2 of the first 4 weeks post-treatment). Weekly decrease (improvement) in responders' mean abdominal pain score (scale range, 0-10) from baseline ranged from -2.6 to -3.3 points during the 18-week follow-up. After the first double-blind repeat treatment, a significantly higher percentage of rifaximin-treated patients were abdominal pain responders (53.9% [172/319]) vs placebo (44.4% [134/302], P = 0.02), with similar results after the second repeat treatment (52.9% [155/293] vs 44.7% [123/275], respectively, P = 0.047). A significantly higher percentage of rifaximin-treated patients were weekly abdominal pain responders for ≥50% of the 18-week double-blind repeat treatment phase (47.9% [138/288] vs 35.9% [97/270], P = 0.004)., Discussion: Rifaximin is efficacious in improving abdominal pain in adults with IBS-D.

Objectives: The nonsystemic antibiotic rifaximin is indicated for irritable bowel syndrome with diarrhea (IBS-D) in adults; however, determinants of response remain unclear. The utility of lactulose breath testing (LBT) in predicting response to rifaximin was examined., Methods: Adults with IBS-D received open-label rifaximin 550 mg 3 times daily for 2 weeks, followed by a 4-week posttreatment assessment period. Thirteen centers prospectively participated in this substudy. LBT was conducted before (day 1) and after (day 14) therapy (breath samples obtained every 15 minutes; up to 240 minutes). Patient response (decrease from baseline of ≥30% in abdominal pain and ≥50% decrease in frequency of mushy/watery stool), symptom improvement, and the relationship of clinical outcomes to LBT results were assessed., Results: A total of 93 patients were included; 62 (66.7%) had positive baseline LBT results. Overall, 48.4% (45/93) of patients responded to rifaximin; of these, 59.7% (37/62) had a positive baseline LBT vs 25.8% (8/31) with a negative LBT (P = 0.002; odds ratio 4.3, 95% confidence interval, 1.5-12.7). Patients with a positive baseline LBT result experienced significantly greater improvement from baseline in 6 of 7 individual IBS symptoms. LBT results after rifaximin therapy did not correlate with clinical response in the 86 patients with evaluable breath tests (P = 0.21); however, patients whose LBT results normalized after rifaximin had the highest response rate of 76.5% (13/17)., Discussion: A positive baseline LBT result predicted a higher likelihood of response to rifaximin in IBS-D, suggesting a gut microbiome modulatory mechanism of action for rifaximin.

Background: ELISA testing for anti-CdtB and anti-vinculin can discriminate patients with irritable bowel syndrome with diarrhea (IBS-D) from those with inflammatory bowel disease (IBD). However, recent findings suggest the antigens can suffer from epitope instability., Aim: This study aimed to assess effects of incorporating epitope stabilization on test characteristics for distinguishing IBS-D from IBD subjects., Methods: Plasma samples from IBS-D subjects from a large-scale clinical trial and subjects with endoscopically active IBD without concurrent immunomodulator therapy were used. After epitope stabilization, CdtB and vinculin were used in ELISA testing. Optical density readings were compared between IBS-D and IBD subjects., Results: Samples from 100 IBS-D and 31 IBD (22 UC and 9 CD) subjects were tested. IBS-D subjects had higher anti-CdtB titers (P = 0.0001) and higher anti-vinculin titers (P = 0.004) than IBD subjects. The specificities of anti-CdtB and anti-vinculin to differentiate IBS-D from IBD were 93.5% and 90.9%, respectively, with sensitivities of 43.0% and 52.2%, respectively. The positive likelihood ratios of identifying IBS-D with anti-CdtB and anti-vinculin were 6.7 and 5.7, respectively. Assuming a pretest probability of 57% for diagnosis of IBS-D in patients with abdominal pain and change in bowel habits, testing positive for both antibodies resulted in a posttest probability of > 98%., Conclusions: Performing epitope stabilization for CdtB and vinculin enhances the test characteristics of ELISAs for anti-CdtB and anti-vinculin in discriminating IBS-D from IBD. Measurement of anti-CdtB and anti-vinculin with this second-generation methodology may further advance our understanding of the role of immunity in functional bowel diseases.

Irritable bowel syndrome (IBS), a complex disorder of the gastrointestinal tract, is characterized by abdominal pain associated with defecation or changes in stool form or frequency. IBS is associated with substantial burden, including direct medical costs and indirect costs. Direct costs associated with IBS in the United States have been estimated to exceed $1 billion. However, indirect costs, such as negative effect on quality of life (QOL) and work productivity, are difficult to quantify. There are 3 main subtypes: IBS with prominent diarrhea (IBS-D), IBS with constipation, and IBS with mixed symptoms of both constipation and diarrhea. A number of pharmacologic agents have been used to treat IBS-D despite lack of approval by the FDA for this indication. The pharmacologic agents that are indicated by the FDA for the treatment of IBS-D include alosetron, eluxadoline, and rifaximin. The negative impact of IBS-D symptoms on QOL reported by patients indicate there is an unmet need for therapies that effectively treat and manage the symptoms of this condition. Addressing gaps in treatment is an important priority.

Background: Antibodies to cytolethal distending toxin B (CdtB) and vinculin are novel biomarkers that rule-in and differentiate irritable bowel syndrome with diarrhea (IBS-D) from other causes of diarrhea and healthy controls., Aim: To determine whether these antibodies can also diagnose and differentiate other IBS subtypes., Methods: Subjects with IBS-D based on Rome III criteria (n = 2375) were recruited from a large-scale multicenter clinical trial (TARGET 3). Healthy subjects without gastrointestinal (GI) diseases or symptoms (n = 43) and subjects with mixed IBS (IBS-M) (n = 25) or IBS with constipation (IBS-C) (n = 30) were recruited from two major medical centers. Plasma levels of anti-CdtB and anti-vinculin antibodies in all subjects were determined by enzyme-linked immunosorbent assay. Optical densities of ≥1.68 and ≥2.80 were considered positive for anti-vinculin and anti-CdtB, respectively. Plasma levels of anti-CdtB and anti-vinculin antibodies were highest in IBS-D and lowest in IBS-C and healthy controls (P < 0.001). Levels in IBS-C subjects were not statistically different from controls (P > 0.1). Positivity for anti-CdtB or anti-vinculin resulted in a statistically significant negative gradient from IBS-D (58.1%) to IBS-M (44.0%), IBS-C (26.7%), and controls (16.3%) (P < 0.001)., Conclusions: Anti-CdtB and anti-vinculin titers and positivity rates differ in IBS subtypes, with higher antibody levels and positivity rates in IBS-D and IBS-M, and lower levels in IBS-C subjects that are similar to those in healthy controls. These antibodies appear useful in the diagnosis of IBS-M and IBS-D, but not IBS-C. Furthermore, these findings suggest that IBS-C is pathophysiologically distinct from subtypes with diarrheal components (i.e., IBS-M and IBS-D).

Purpose: A high incidence of irritable bowel syndrome (IBS) is associated with significant medical costs. Diarrhea-predominant IBS (IBS-D) is diagnosed on the basis of clinical presentation and diagnostic test results and procedures that exclude other conditions. This study was conducted to estimate the potential cost savings of a novel IBS diagnostic blood panel that tests for the presence of antibodies to cytolethal distending toxin B and anti-vinculin associated with IBS-D., Methods: A cost-minimization (CM) decision tree model was used to compare the costs of a novel IBS diagnostic blood panel pathway versus an exclusionary diagnostic pathway (ie, standard of care). The probability that patients proceed to treatment was modeled as a function of sensitivity, specificity, and likelihood ratios of the individual biomarker tests. One-way sensitivity analyses were performed for key variables, and a break-even analysis was performed for the pretest probability of IBS-D. Budget impact analysis of the CM model was extrapolated to a health plan with 1 million covered lives., Findings: The CM model (base-case) predicted $509 cost savings for the novel IBS diagnostic blood panel versus the exclusionary diagnostic pathway because of the avoidance of downstream testing (eg, colonoscopy, computed tomography scans). Sensitivity analysis indicated that an increase in both positive likelihood ratios modestly increased cost savings. Break-even analysis estimated that the pretest probability of disease would be 0.451 to attain cost neutrality. The budget impact analysis predicted a cost savings of $3,634,006 ($0.30 per member per month)., Implications: The novel IBS diagnostic blood panel may yield significant cost savings by allowing patients to proceed to treatment earlier, thereby avoiding unnecessary testing., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The role of gut microbiota in the pathophysiology of irritable bowel syndrome (IBS) is supported by various lines of evidence, including differences in mucosal and faecal microbiota between patients with IBS and healthy individuals, development of post-infectious IBS, and the efficacy of some probiotics and nonsystemic antibiotics (e.g. rifaximin)., Aim: To review the literature regarding the role of rifaximin in IBS and its potential mechanism(s) of action., Methods: A literature search was conducted using the terms 'rifaximin', 'irritable bowel syndrome' and 'mechanism of action'., Results: Rifaximin was approved in 2015 for the treatment of IBS with diarrhoea. In contrast to other currently available IBS therapies that require daily administration to maintain efficacy, 2-week rifaximin treatment achieved symptom improvement that persisted ≥12 weeks post-treatment. The mechanisms of action of rifaximin, therefore, may extend beyond direct bactericidal effects. Data suggest that rifaximin may decrease host proinflammatory responses to bacterial products in patients with IBS. In some cases, small intestinal bacterial overgrowth (SIBO) may play a role in the clinical symptoms of IBS. Because of the high level of solubility of rifaximin in the small intestine, rifaximin may reset microbial diversity in this environment. Consistent with this hypothesis, rifaximin has antibiotic efficacy against isolates derived from patients with SIBO., Conclusion: Resetting microbial diversity via rifaximin use may lead to a decrease in bacterial fermentation and a reduction in the clinical symptoms of IBS., (© 2015 John Wiley & Sons Ltd.)

Diarrhea-predominant irritable bowel syndrome (IBS) is diagnosed through clinical criteria after excluding "organic" conditions, and can be precipitated by acute gastroenteritis. Cytolethal distending toxin B (CdtB) is produced by bacteria that cause acute gastroenteritis, and a post-infectious animal model demonstrates that host antibodies to CdtB cross-react with vinculin in the host gut, producing an IBS-like phenotype. Therefore, we assessed circulating anti-CdtB and anti-vinculin antibodies as biomarkers for D-IBS in human subjects. Subjects with D-IBS based on Rome criteria (n=2375) were recruited from a large-scale multicenter clinical trial for D-IBS (TARGET 3). Subjects with inflammatory bowel disease (IBD) (n=142), subjects with celiac disease (n=121), and healthy controls (n=43) were obtained for comparison. Subjects with IBD and celiac disease were recruited based on the presence of intestinal complaints and histologic confirmation of chronic inflammatory changes in the colon or small intestine. Subjects with celiac disease were also required to have an elevated tTG and biopsy. All subjects were aged between 18 and 65 years. Plasma levels of anti-CdtB and anti-vinculin antibodies were determined by ELISA, and compared between groups. Anti-CdtB titers were significantly higher in D-IBS subjects compared to IBD, healthy controls and celiac disease (P<0.001). Anti-vinculin titers were also significantly higher in IBS (P<0.001) compared to the other groups. The area-under-the-receiver operating curves (AUCs) were 0.81 and 0.62 for diagnosis of D-IBS against IBD for anti-CdtB and anti-vinculin, respectively. Both tests were less specific in differentiating IBS from celiac disease. Optimization demonstrated that for anti-CdtB (optical density≥2.80) the specificity, sensitivity and likelihood ratio were 91.6%, 43.7 and 5.2, respectively, and for anti-vinculin (OD≥1.68) were 83.8%, 32.6 and 2.0, respectively. These results confirm that anti-CdtB and anti-vinculin antibodies are elevated in D-IBS compared to non-IBS subjects. These biomarkers may be especially helpful in distinguishing D-IBS from IBD in the workup of chronic diarrhea.

Background: The recent FDA provisional endpoint incorporates a one-tailed measure of improvement for IBS based on the underlying motility complaint. However, motility exists along a spectrum. Patients may experience diarrhoea resulting from therapy for their constipation-predominant IBS (IBS-C) or constipation during treatment for diarrhoea-predominant IBS (IBS-D), but still meet a unidirectional motility-based FDA endpoint., Aim: To weigh the reported efficacy of existing therapies based on patient-reported outcomes with negative intestinal side effects in controlled clinical trial data., Methods: We analysed the difference between 'attributable risk' of efficacy based on number needed to treat (NNT) in the literature and percentage of adverse events (AE) of opposite intestinal complaints in placebo-controlled trials identified through a literature search of IBS trials. This calculation was coined 'functional net value' (FNV) or net benefit of the given drug., Results: For treating IBS-C, lubiprostone caused diarrhoea in excess of placebo in 3.9% of patients, leading to a FNV of 3.9 percentage units. Linaclotide caused diarrhoea in 15.3% resulting in negative FNV (-1.0 percentage unit). For IBS-D, alosetron and tricyclic anti-depressants caused constipation among a respective 16.9% and 13.0% resulting in a FNV of -3.6 and -0.5 percentage units. Among all therapies, only rifaximin did not cause the adverse event opposite the underlying motility complaint and the drug only had benefit, not detriment., Conclusions: Functional net value (FNV) offers a method of evaluating the net benefit of a drug in IBS. Most IBS treatments have a negative effect on IBS that exceeds the benefits., (© 2014 John Wiley & Sons Ltd.)

Objectives: In drug trials involving subjects with irritable bowel syndrome (IBS), the placebo effect seems to be very important. However, events even before starting the study may also impact patient expectations. In this study, we utilized consent language from prior studies of diarrhea predominant IBS (D-IBS) drug trials to determine whether the knowledge imparted during this process affects the response to different therapies., Methods: Consecutive IBS subjects who met the Rome III criteria for IBS were enrolled. Patients were presented with a mock trial and randomized to 1 of 3 questionnaires with consent using similar language from consent forms of 3 drugs used in D-IBS: desipramine, alosetron, and rifaximin. Demographics, IBS symptoms using visual analog scale, and percent improvement needed for patients to report adequate relief of IBS from theoretically taking their assigned drug was asked. Data were expressed as mean ± SE., Results: Subjects who were anticipating rifaximin had the highest expectation of improvement to determine adequate relief of 87.3 ± 10.9% compared with 73.4 ± 18.0% for desipramine (P<0.01) and 76.8 ± 20% for alosetron (P=0.049). There was no major difference in expectation of response from any medication to satisfy adequate relief on the basis of a belief that IBS is psychologic or organic in origin. In addition, sex and previous use of a drug did not influence the expectation of adequate relief., Conclusions: Benefits of drugs in D-IBS drug trials have the potential to be influenced by preconceived notions derived from familiarity of drug class and the consent process even before the study begins which we refer to as the "pre-cebo" effect. The higher pre-cebo effect for rifaximin may be an obstacle to successful treatment effect during drug trials compared with drugs such as desipramine. The pre-cebo effect may need to be taken into account when formulating consent forms for IBS study.

Background: Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder characterized by alterations in bowel function, abdominal discomfort, and bloating. The symptoms of IBS vary widely between constipation and diarrhea predominance. In this study, we examine "constipation minus diarrhea" score (C-D) to account for the contribution of diarrhea and to create a reliable method for predicting constipation predominance in IBS., Methods: A nested study was conducted in participants with IBS by Rome I criteria. After consent, they completed a daily stool diary for 1 week. This included recording frequency of bowel movements and describing consistency of stool using the Bristol stool scale. After submitting their diaries, participants rated their bowel symptoms using a visual analog score (VAS) scale from 0 to 100 mm, with 100 mm representing maximum severity. VAS scores for C, D, and C-D were subsequently compared with the true stool events of the previous week by stool diary to validate the potential usefulness of the simple C-D method., Results: Eighty-four participants with IBS completed stool diaries and VAS surveys for bowel symptoms, from which C-D scores were compiled. By correcting for the predominance of constipation compared with diarrhea, C-D scores predicted constipation based on the frequency of bowel movements and Bristol stool score. Furthermore, a second method was used to validate the C-D technique by comparing the mean C-D score in participants with constipation (≤3 d with bowel movement in previous week). In this case, the mean C-D score was 74.1 ± 3.8 compared with -3.0 ± 5.9 for patients with >3 days with bowel movement in that week (P<0.001). Although the constipation severity alone also distinguished these 2 groups, the difference was less impressive (P<0.01). In participants with mean Bristol stool scores of ≤2 in the preceding week, the C-D mean score was 25.4 ± 6.1 compared with participants having mean Bristol stool score of >2 where the C-D was -11.1 ± 5.9 (P<0.01). Using constipation severity by VAS alone, there was no significant difference between these same 2 Bristol stool categories (P=0.29)., Conclusions: IBS patients' self-assessment of constipation and diarrhea severity using the C-D score is an effective predictor of C-IBS and constipation severity. The C-D score may be a useful tool in future IBS constipation trials, as it seems to predict constipation and it correlates well with stool diaries.

Background: A significant gender disparity has been observed in individuals with irritable bowel syndrome (IBS), with females outnumbering males, especially in constipation-predominant IBS (C-IBS). However, this observation is based on Rome criteria categorization and does not take into account the severity of constipation or diarrhea., Objective: In a large prospective data set, gender differences across the severity of constipation and diarrhea were examined in patients with IBS., Methods: Consecutive adult patients with Rome I positive IBS who were referred to a tertiary care medical center (Cedars-Sinai Medical Center, Los Angeles, California) in 1999-2003 were given a questionnaire. The questionnaire asked subjects to rate their constipation and diarrhea according to perceived severity using a scale from 0 (none) to 5 (very severe). C-IBS was determined to be present if the severity of constipation was greater than the severity of diarrhea (sevC > sevD). If sevD > sevC, subjects were considered to have diarrhea-predominant IBS (D-IBS). To further categorize their symptoms, subjects were then grouped by the difference between the severity of constipation and diarrhea, creating a range of values from -5 to +5. For each of these 11 constipation/diarrhea severity values, the female:male ratio was determined. The severity of constipation to diarrhea was compared by Spearman rank correlation., Results: A total of 429 subjects with IBS (325 women: mean [SD] age, 42.5 [0.8] years; 104 men: mean age, 42.2 [1.7] years) completed the questionnaire. Constipation occurred more frequently in women (79.7%) compared with men (61.5%) (odds ratio [OR] = 2.49; 95% CI, 1.55-4.02). The prevalence of diarrhea was similar between the sexes. Whereas C-IBS was more common in women (31.8%) than in men (26.0%) (OR = 2.03; 95% CI, 1.24-3.30), D-IBS was more prevalent in men (62.5%) than in women (36.3%) (OR = 2.39; 95% CI, 1.53-3.75). When the female:male ratio was evaluated across the 11 severity score categories of constipation and diarrhea, the greater the sevC - sevD score, the higher the proportion of women (R = 0.80; P = 0.003)., Conclusion: In this study of patients with IBS, the observation of the association of constipation and gender in IBS is extended to indicate that the female:male ratio significantly increases according to the severity of constipation relative to the severity of diarrhea., (Copyright (c) 2010 Excerpta Medica Inc. All rights reserved.)

Modern methods of diagnosing diarrhea-predominant irritable bowel syndrome (D-IBS) require a "diagnosis of exclusion" approach. In this study we aim to test the diagnostic ability of using the fluctuation of frequency and consistency of bowel patterns in IBS to discriminate it from other causes of diarrhea. Eligible subjects were asked to complete a questionnaire on the changes in form and frequency of bowel habits by time. The primary endpoint was to evaluate the diagnostic effectiveness of having irregularly irregular bowel function and form as more characteristic of IBS versus non-IBS causes. Patients were prospectively recruited from a tertiary care GI clinic. Subjects had to have diarrhea as their primary complaint. In the case of IBS, D-IBS subjects were recruited. Subjects with celiac disease, Crohn's and ulcerative colitis were recruited for comparison and were categorically called "non-IBS." Non-IBS subjects could not have a recent history of blood in stool or a history of bowel surgery, fistulae or narcotic use. Sixty-two IBS and 37 non-IBS subjects were recruited. Among the 62 IBS subjects, 49 (79%) stated that their bowel habits varied in form and frequency on a daily basis compared to 35% in non-IBS subjects (OR = 8.9, CI = 3.5-22.5, P < 0.00001). When subjects were compared by the number of different stool forms they had witnessed in the prior week, IBS subjects noted 3.58 +/- 0.19 types and non-IBS reported 2.35 +/- 0.16 (P < 0.00001). Using > or = 3 stool forms per week as a method of discriminating IBS from non-IBS, 50 out of 62 subjects with IBS (81%) reported this greater number of forms compared to 15 out of 37 (41%) non-IBS subjects (sensitivity = 0.81; specificity = 0.60). The use of this simple tool that identifies an irregularly irregular bowel form and function is successful in separating D-IBS from non-IBS subjects.

Three hundred and fifty two medical records of AIDS inpatients were analysed in a retrospective study to establish the frequency, clinical patterns and etiology of AIDS-related diarrhea. Diarrhea was observed in 58.8% of the patients, being a chronic symptom in 65.7%, and the first complaint in 24.6%. The most common cause of diarrhea was coccidea and the etiology remained unknown in 56.1% of the patients. Routine stool examination was the most sensitive method in the diagnosis of diarrhea. In countries with limited resources, the use of stool examinations seems to provide appropriate clinical management. The implementation of an objective protocol could improve the etiologic diagnosis of AIDS-related diarrhea without the burden of more complex and invasive technologies.

Cryptolepine is the main alkaloid of Cryptolepis sanguinolenta (Lindl.) Schlechter, a plant used in traditional medicine in West Africa. The minimal inhibitory concentrations (MICs) of cryptolepine, ethanol and aqueous extracts of Cryptolepis sanguinolenta root were determined for 65 strains of Campylobacter jejuni, 41 strains of Campylobacter coli isolated from sporadic cases of gastroenteritis in Portugal and 86 strains of Vibrio cholerae isolated from patients with enteric infections in Angola, Brazil and Portugal. The ethanol extract activity against Campylobacter strains (MIC90% = 25 micrograms/ml) is higher than that of co-trimoxazole and sulfamethoxazole and Campylobacter strains susceptibility for cryptolepine (MIC90% = 12.5 micrograms/ml) is equal for ampicillin. The ethanol extract and cryptolepine show some activity against the Vibrio cholerae strains, although their activities are lower than that of tetracycline. The results suggest that these roots could be a therapeutic alternative for bacterial etiologic diarrhoea in West Africa.