Evelyn J. Chow

Eradication of small intestinal bacterial overgrowth reduces symptoms of irritable bowel syndrome

OBJECTIVES:Irritable bowel syndrome is the most common gastrointestinal diagnosis. The symptoms of irritable bowel syndrome are similar to those of small intestinal bacterial overgrowth. The purpose of this study was to test whether overgrowth is associated with irritable bowel syndrome and whether treatment of overgrowth reduces their intestinal complaints.METHODS:Two hundred two subjects in a prospective database of subjects referred from the community undergoing a lactulose hydrogen breath test for assessment of overgrowth were Rome I criteria positive for irritable bowel syndrome. They were treated with open label antibiotics after positive breath test. Subjects returning for follow-up breath test to confirm eradication of overgrowth were also assessed. Subjects with inflammatory bowel disease, abdominal surgery, or subjects demonstrating rapid transit were excluded. Baseline and after treatment symptoms were rated on visual analog scales for bloating, diarrhea, abdominal pain, defecation relief, mucous, sensation of incomplete evacuation, straining, and urgency. Subjects were blinded to their breath test results until completion of the questionnaire.RESULTS:Of 202 irritable bowel syndrome patients, 157 (78%) had overgrowth. Of these, 47 had follow-up testing. Twenty-five of 47 follow-up subjects had eradication of small intestinal bacterial overgrowth. Comparison of those that eradicated to those that failed to eradicate revealed an improvement in irritable bowel syndrome symptoms with diarrhea and abdominal pain being statistically significant after Bonferroni correction (p < 0.05). Furthermore, 48% of eradicated subjects no longer met Rome criteria (χ2= 12.0, p < 0.001). No difference was seen if eradication was not successful.CONCLUSIONS:Small intestinal bacterial overgrowth is associated with irritable bowel syndrome. Eradication of the overgrowth eliminates irritable bowel syndrome by study criteria in 48% of subjects.

Normalization of Lactulose Breath Testing Correlates With Symptom Improvement in Irritable Bowel Syndrome: A Double-Blind, Randomized, Placebo-Controlled Study

OBJECTIVE:We have recently found an association between abnormal lactulose breath test (LBT) findings and irritable bowel syndrome (IBS). The current study was designed to test the effect of antibiotic treatment for IBS in a double-blind fashion.METHODS:Consecutive IBS subjects underwent an LBT with the results blinded. All subjects were subsequently randomized into two treatment groups (neomycin or placebo). The prevalence of abnormal LBT was compared with a gender-matched control group. Seven days after completion of treatment, subjects returned for repeat LBT. A symptom questionnaire was administered on both days.RESULTS:After exclusion criteria were met, 111 IBS subjects (55 neomycin, 56 placebo) entered the study, with 84% having an abnormal LBT, compared with 20% in healthy controls (p < 0.01). In an intention-to-treat analysis of all 111 subjects, neomycin resulted in a 35.0% improvement in a composite score, compared with 11.4% for placebo (p < 0.05). Additionally, patients reported a percent bowel normalization of 35.3% after neomycin, compared with 13.9% for placebo (p < 0.001). There was a graded response to treatment, such that the best outcome was observed if neomycin was successful in normalizing the LBT (75% improvement) (one-way ANOVA, p < 0.0001). LBT gas production was associated with IBS subgroup, such that methane excretion was 100% associated with constipation-predominant IBS. Methane excretors had a mean constipation severity of 4.1, compared with 2.3 in all other subjects (p < 0.001).CONCLUSIONS:An abnormal LBT is common in subjects with IBS. Normalization of LBT with neomycin leads to a significant reduction in IBS symptoms. The type of gas seen on LBT is also associated with IBS subgroup.

Methane Production During Lactulose Breath Test Is Associated with Gastrointestinal Disease Presentation

It has recently been determined that there is an increased prevalence of bacterial overgrowth in IBS. Since there are two gases (hydrogen and methane) measured on lactulose breath testing, we evaluated whether the different gas patterns on lactulose breath testing coincide with diarrhea and constipation symptoms in IBS and IBD. Consecutive patients referred to the gastrointestinal motility program at Cedars-Sinai Medical Center for lactulose breath testing were given a questionnaire to evaluate their gastrointestinal symptoms. Symptoms were graded on a scale of 0–5. Upon completion of the breath test, the results were divided into normal, hydrogen only, hydrogen and methane, and methane only positive breath tests. A comparison of all subjects and IBS subjects was undertaken to evaluate diarrhea and constipation with regards to the presence or absence of methane. This was further contrasted to Crohns and ulcerative colitis (UC) patients in the database. After exclusion criteria, 551 subjects from the database were available for comparison. Of the 551 subjects (P < 0.05, one-way ANOVA) and in a subgroup of 296 IBS subjects (P < 0.05, one-way ANOVA), there was a significant association between the severity of reported constipation and the presence of methane. The opposite was true for diarrhea (P < 0.001). If a breath test was methane positive, this was 100% associated with constipation predominant IBS. Furthermore, IBS had a greater prevalence of methane production than Crohns or UC. In fact, methane was almost nonexistent in the predominantly diarrheal conditions of Crohns and UC. In conclusion, a methane positive breath test is associated with constipation as a symptom.

Neomycin Improves Constipation-Predominant Irritable Bowel Syndrome in a Fashion That Is Dependent on the Presence of Methane Gas: Subanalysis of a Double-Blind Randomized Controlled Study

Recent studies have shown that normalization of the lactulose breath test (LBT) with neomycin leads to a significant reduction in irritable bowel syndrome (IBS) symptoms. This subanalysis was done on the constipation-predominant IBS subgroup of patients (C-IBS) to test the ability of neomycin to improve constipation and its correlation with the elimination of methane on breath test. IBS subjects underwent LBT in a blinded fashion. They were then randomly allocated to neomycin or placebo groups. For the purpose of this analysis, only the C-IBS subjects were identified. They were then evaluated for global improvement, abdominal pain, and constipation severity. The ability of neomycin to eliminate methane and its associated improvement in constipation was also determined. One hundred eleven subjects meeting Rome I criteria for IBS were included in the study. Thirty-nine of these had C-IBS. Of these, 20 received placebo and 19 received neomycin. With neomycin, a global improvement of 36.7±7.9% was seen, compared to 5.0±3.2% for placebo (P < .001) in the intention-to-treat analysis. Constipation was improved by 32.6±9.9% with neomycin compared to 18.7±7.2% for placebo (P=.26). Of the original 111 subjects, 12 demonstrated methane on breath test. All 12 of these patients were constipation predominant. In the methane producers receiving neomycin or placebo, improvement in constipation was significantly greater in those receiving neomycin (44.0±12.3%) compared to placebo (5.0±5.1%) (P < .05). Treatment with neomycin improves constipation in C-IBS. This improvement depends on the presence and elimination of methane on breath test.

Lower frequency of MMC is found in IBS subjects with abnormal lactulose breath test, suggesting bacterial overgrowth.

We have recently described an association between irritable bowel syndrome (IBS) and abnormal lactulose breath test, suggesting small intestinal bacterial overgrowth (SIBO). However, the mechanism by which SIBO develops in IBS is unknown. In this case–control study we evaluate the role of small intestinal motility in subjects with IBS and SIBO. Small intestinal motility was studied in consecutive IBS subjects with SIBO on lactulose breath test. After fluoroscopic placement of an eight-channel water-perfused manometry catheter, 4-hr fasting recordings were obtained. Based on this, the number and duration of phase III was compared to 30 control subjects. To test whether there was a relationship between the motility abnormalities seen and the SIBO status of the patient at the time of the motility, subjects with a breath test within 5 days of the antroduodenal manometry were also compared. Sixty-eight subjects with IBS and SIBO were compared to controls. The number of phase III events was 0.7 ± 0.8 in IBS subjects and 2.2 ± 1.0 in controls (P < 0.000001). The duration of phase III was 305 ± 123 sec in IBS subjects and 428 ± 173 in controls (P < 0.001). Subjects whose SIBO was still present at the time of manometry had less frequent phase III events than subjects with eradicated overgrowth (P < 0.05). In conclusion, phase III is reduced in subjects with IBS and SIBO. Eradication of bacterial overgrowth seems to result in some normalization of motility.

Identification of a prodromal period in Crohn's disease but not ulcerative colitis.

OBJECTIVES:Irritable bowel syndrome, a common gastrointestinal diagnosis, has not been clearly studied in inflammatory bowel disease. Some of the residual symptoms in subjects treated with Crohns disease and ulcerative colitis are thought to be related to irritable bowel syndrome. The aims of this study were 1) to describe the duration and nature of complaints before the diagnosis of Crohns disease and ulcerative colitis (prodromal period), and 2) to determine the role of IBS in this prodromal period.METHODS:A total of 66 patients with confirmed inflammatory bowel disease were enrolled in the study. The subjects received a questionnaire to ascertain the nature and duration of symptoms preceding the diagnosis of Crohns disease or ulcerative colitis, including features described under the Rome criteria for irritable bowel syndrome.RESULTS:Of the 66 subjects analyzed, 45 had Crohns disease and 21 had ulcerative colitis. The prodromal period was 7.7 ± 10.7 yr for Crohns disease and 1.2 ± 1.8 yr for ulcerative colitis (p < 0.05). Once patients meeting the Rome criteria for irritable bowel syndrome during the prodrome were excluded, the duration of the prodromal period (non-IBS) for ulcerative colitis dropped to 0.8 ± 1.3 yr compared to 6.9 ± 9.8 yr in the Crohns disease group (p < 0.05). The symptoms of the non-IBS prodrome in subjects with Crohns disease were bloating, diarrhea, stomach pain, heartburn, fever, weight loss, and fatigue. Further analysis demonstrated that subjects whose Crohns disease initially began as colonic disease had a longer prodrome than with small bowel. In the non-IBS Crohns group, there was also a correlation between the age at the time of diagnosis and the duration of prodrome (r = 0.67, p < 0.0001).CONCLUSIONS:There is a significant prodromal period before the time of diagnosis of Crohns disease that is not found in ulcerative colitis even after exclusion of subjects with IBS.

Peppermint oil improves the manometric findings in diffuse esophageal spasm.

Background Diffuse esophageal spasm (DES) is an uncommon condition that results in simultaneous esophageal contractions. Current medical treatment of DES is frequently unsatisfactory. We hypothesized that, as a smooth muscle relaxant, peppermint oil may improve the manometric findings in DES. Study Eight consecutive patients with chest pain or dysphagia and who were found to have DES were enrolled during their diagnostic esophageal manometry. An eight-channel perfusion manometry system was used. Lower esophageal sphincter pressure and contractions of the esophageal body after 10 wet swallows were assessed before and 10 minutes after the ingestion of a solution containing five drops of peppermint oil in 10 mL of water. Each swallow was assessed for duration (seconds), amplitude (mm Hg), and proportion of simultaneous and multiphasic esophageal contractions. Results Lower esophageal sphincter pressures and contractile pressures and durations in both the upper and lower esophagus were no different before and after the peppermint oil. Peppermint oil completely eliminated simultaneous esophageal contractions in all patients (p < 0.01). The number of multiphasic, spontaneous, and missed contractions also improved. Because normal esophageal contractions are characteristically uniform in appearance, variability of esophageal contractions was compared before and after treatment. The variability of amplitude improved from 33.4 ± 36.7 to 24.9 ± 11.0 mm Hg (p < 0.05) after the peppermint oil. The variability for duration improved from 2.02 ± 1.80 to 1.36 ± 0.72 seconds (p < 0.01). Two of the eight patients had chest pain that resolved after the peppermint oil. Conclusions This data demonstrates that peppermint oil improves the manometric features of DES.

Small Intestinal Bacterial Overgrowth: A Possible Association with Fibromyalgia

Objectives: Subjects with fibromyalgia [FMS] frequently have non specific bowel complaints similar to subjects with small intestinal bacterial over growth [SIBO]. The aim of this study was to test whether 1. SIBO is prevalent in FMS and 2. If treatment of SIBO reduces bowel symptoms. Methods: Of 815 subjects under going lactulose hydrogen breath testing for assessment of SIBO, 123 patients had FMS. Those with SIBO were treated with antibiotics. At the initial and follow-up visits, subjects were asked to rate their symptoms. Symptom scores be fore and after treatment were com pared. Results: Of the 123 subjects with FMS, 96 [78%] were found to have SIBO. Returning subjects reported a 57 ± 29% over all improvement in symptoms with significant improvement in bloating, gas, abdominal pain, diarrhea, constipation, joint pains, and fatigue [P < 0.05]. Conclusions: 1. Small intestinal bacterial over growth is associated with FMS, 2. Eradication of SIBO improves intestinal symptoms in FMS.