Clinical significance of colonic diverticulosis associated with bowel symptoms and colon polyp

Diverticulosis and cardiometabolic risk factors: a systematic literature review

BACKGROUND

There is a hypothesis of an association between diverticulosis and metabolic syndrome (MS) or its components, but data on this topic are inconsistent, and a systematic review has not been performed. We conducted a systematic review to investigate the possible association between cardiometabolic risk factors and diverticulosis.

METHODS

A systematic literature search was conducted via PubMed, Cochrane Library, and Web of Science in December 2022 to collect the necessary data. Studies that examined the association between MS or individual metabolic factors and asymptomatic diverticulosis were included in the review.

RESULTS

Of the potentially relevant articles identified via PubMed (477), Cochrane Library (224), and Web of Science (296), 29 articles met the inclusion criteria and were used for this work. These studies were assessed for study quality using GRADE. Overall, 6 studies were rated as "very low," 19 studies as "low," and 4 studies as "moderate." The data suggest an association between arterial hypertension, obesity, and fatty liver disease in younger patients and diverticulosis. Patient age appears to play an important role in diverticular formation. Data on diabetes mellitus is inconclusive and may require further investigation depending on the location of the diverticula.

CONCLUSION

Based on the synthesized data, there is an association between arterial hypertension, obesity, and fatty liver disease in younger patients. The formation of diverticula seems to be influenced by age and genetic factors. The study suggests a connection with cardiometabolic risk factors. To gain a better understanding of the role of metabolic risk factors in asymptomatic diverticulosis, targeted studies are necessary based on these findings.

Association of Colonic Diverticula with Colorectal Adenomas and Cancer

Background and Objectives: Conflicting evidence is reported regarding any association between colonic diverticula with colorectal adenomas or cancer. The present study aimed to evaluate, in a cohort of Caucasian patients, the association between colonic diverticula and colorectal polyps and cancer. Materials and Methods: All consecutive patients undergoing colonoscopy at our institution were included in the study. The presence and location of diverticula, polyps, and cancers were recorded. Histologically, polyps were classified as adenoma (with low or high dysplasia), hyperplastic, or inflammatory. The relative risk of the association of polyps and cancer with diverticula was assessed. Multiple logistic regression analyses, including age, sex, family history for colorectal cancer (CRC), and family history for diverticula, were carried out. Results: During the study period, 1490 patients were enrolled; 37.2% (n = 555) showed colonic diverticula or polyps or CRC (308 males, mean age 66 years). Particularly, 12.3% (n = 183) patients presented only diverticula, 13.7% (n = 204) only polyps or cancer, 11.3% (n = 168) both diseases, and 62.7% (n = 935) neither diverticula nor polyps and cancer. A total of 38 patients presented colorectal cancer, 17 of which had also diverticula. A significant increase in relative risk (RR 2.81, 95% CI 2.27-3.47, p < 0.0001) of colorectal adenoma and cancer in patients with colonic diverticula was found. At multivariate analysis, only diverticula resulted to be significantly associated with colorectal adenomas and cancer (Odds Ratio, OR 3.86, 95% CI 2.90-5.14, p < 0.0001). Conclusions: A significant association of colonic diverticula with colorectal adenoma or cancer was found. This implies that patients with colonic diverticula require a vigilant follow-up procedure for the prevention of colorectal cancer from those applicable to the general population.

The relationship between diverticulosis and colorectal neoplasia: A meta-analysis

Background/Aims

Diverticulosis and colorectal neoplasia share epidemiological trends and risk factors which are common in Western countries and incidences increase with age. However, the data on an association between diverticulosis and colorectal neoplasia are conflicting. Thus, we performed a meta-analysis to evaluate whether diverticulosis is associated with colorectal neoplasia.

Methods

A systematic literature search of PubMed, EMBASE, Cochrane Library, Web of Science, and SCOPUS was conducted to identify studies that investigated the association between diverticulosis and advanced colorectal neoplasia (advanced adenoma, colorectal cancer), adenomas, or polyps. The demographic characteristics of patients, including age, gender, indication for colonoscopy, confounding factors, and outcomes of colorectal neoplasia were assessed.

Results

We identified 29 cross-sectional studies (N = 450,953) that investigated the association between diverticulosis and colorectal neoplasia. The meta-analysis found that diverticulosis was not associated with advanced colorectal neoplasia (odds ratio [OR] 0.98, 95% confidence interval [CI] 0.63–1.50). Although there was a positive correlation between diverticulosis and adenomas (OR 1.47, 95% CI 1.18–1.84) and diverticulosis and polyps (OR 1.95, 95% CI 1.15–3.31), diverticulosis did not increase the risk of adenomas (OR 1.34, 95% CI 0.87–2.06) in patients who underwent screening colonoscopy. Moreover, all the increased risk of colorectal neoplasia in patients with diverticulosis was observed in published studies only, and not in unpublished ones.

Conclusions

This meta-analysis demonstrated that diverticulosis is not associated with an increased risk of advanced colorectal neoplasia. Although diverticulosis was associated with a higher risk of polyps and adenomas, the risk was not increased in screening populations. Moreover, the increased risk of colorectal neoplasia in patients with diverticulosis was observed only in published studies and not in unpublished ones.

Does Colonic Diverticulosis Raise the Risk of Colorectal Adenoma in Patients with Colorectal Cancer?

Background

The aim of this study was to evaluate the risk of development of colorectal adenomas in patients with colorectal cancer (CRC) with and without colonic diverticulosis.

Methods

We performed a retrospective cohort study that included patients with CRC between 2008 and 2011. All patients underwent preoperative colonoscopic and barium enema examinations. Follow-up colonoscopic examinations were performed within 1 year and between 3 and 5 years postoperatively. The incidence of colorectal adenomas was compared based on the presence or absence of diverticulosis. Additionally, multivariate logistic regression analysis was performed to identify the factors independently associated with the development of synchronous and metachronous colorectal adenomas.

Results

Of the 168 patients with CRC included in the study, 55 showed colonic diverticulosis. Synchronous colorectal adenomas were more common in CRC patients with diverticulosis than in those without diverticulosis (P > 0.001). Multivariate regression analysis showed that colonic diverticulosis (odds ratio (OR) 3.874, 95% confidence interval (CI) 1.843–8.144, P > 0.001) and obesity (body mass index > 25.0 kg/m², OR 2.395, 95% CI 1.089–5.270, P = 0.030) were associated with an increased risk of synchronous colorectal adenomas. The presence of synchronous colorectal adenomas increased the risk of metachronous colorectal adenomas (OR 4.407, 95% CI 1.855–10.473, P > 0.001).

Conclusions

Colonic diverticulosis was associated with synchronous colorectal adenomas in patients with CRC, which is eventually increasing the risk of metachronous adenomas.

Factors associated with diverticular bleeding and re-bleeding: A United States hospital study

OBJECTIVE:

Diverticular bleeding is the most common cause of lower gastrointestinal bleeding. Arteriovascular disease, metabolic syndromes, non-steroidal anti-inflammatory drugs (NSAIDs), anti-thrombotics, and anticoagulants have been suggested as risk factors. There is a paucity of studies addressing factors associated with diverticular re-bleeding, especially in the United States. The aim of this study is to evaluate factors associated with colonic diverticular bleeding and re-bleeding in a US community-based hospital.

METHODS:

We conducted a retrospective case-control study to analyze the factors associated with diverticular bleeding. Between January 2010 and July 2011, 93 patients were admitted to our hospital with a primary diagnosis of acute diverticular bleeding. We compared them to 152 patients who were admitted with a primary diagnosis of diverticulitis in the same period. We collected data from the medical records of each patient in relation to the demographics, comorbidities, medications, social habits, location of diverticulosis, length of stay in the hospital, and re-bleeding rate within 2 years of the first bleeding episode.

RESULTS:

Factors such as cerebrovascular accident (p=0.009), coronary artery disease (p=0.037), diabetes mellitus (p=0.046), obstructive sleep apnea (p=0.033), NSAIDs (p=0.038), use of anti-thrombotics (p=0.001), anticoagulants (p=0.002) or calcium channel blockers (p=0.009), and bilateral diverticulosis (p=0.001) were significantly associated with diverticular bleeding as compared to diverticulitis. Recurrence of bleeding was noted in 26 out of 93 patients (28%) within 2 years of the first bleeding episode (p=0.001). Bilateral colonic involvement, anticoagulants, and elderly age (≥65 years) were found to have a closer relationship to diverticular re-bleeding, although it was not statistically significant.

CONCLUSION:

This study reveals that arteriovascular disease, diabetes mellitus, NSAIDs, the use of anti-thrombotics, anticoagulants or calcium channel blockers, and obstructive sleep apnea are factors that are significantly associated with diverticular bleeding. It also shows that bilateral colonic involvement, elderly age, and anticoagulants have a closer relationship to diverticular re-bleeding. More prospective studies in patients with diverticular bleeding should be conducted to shed light on the causality of these factors and the prevalence of diverticulitis.

The association between a positive lactulose methane breath test and rectocele in constipated patients

OBJECTIVES

Rectocele with constipation might be related to methane (CH4) producing intestinal bacteria. We investigated the breath CH4 levels and the clinical characteristics of colorectal motility in constipated patients with rectocele.

METHODS

A database of consecutive female outpatients was reviewed for the evaluation of constipation according to the Rome III criteria. The patients underwent the lactulose CH4 breath test (LMBT), colon marker study, anorectal manometry, defecography and bowel symptom questionnaire. The profiles of the lactulose breath test (LBT) in 33 patients with rectocele (with size ≥ 2 cm) and 26 patients with functional constipation (FC) were compared with the breath test results of 30 healthy control subjects.

RESULTS

The mean size of rectocele was 3.52 ± 1.06 cm. The rate of a positive LMBT (LMBT+) was significantly higher in patients with rectocele (33.3%) than in those with FC (23.1%) or healthy controls (6.7%) (p = 0.04). Breath CH4 concentration was positively correlated with rectosigmoid colon transit time in rectocele patients (γ = 0.481, p < 0.01). A maximum high pressure zone pressure > 155 mmHg was a significant independent factor of LMBT+ in rectocele patients (OR = 8.93, 95% CI = 1.14-71.4, p = 0.04).

CONCLUSIONS

LMBT+ might be expected in constipated patients with rectocele. Moreover, increased rectosigmoid colonic transit or high anorectal pressure might be associated with CH4 breath levels. Breath CH4 could be an important therapeutic target for managing constipated patients with rectocele.

Low frequency of polyps in colonic regions with diverticulosis

PURPOSE

Conflicting evidence exists regarding any association between diverticulosis and adenomatous polyps. We evaluated the prevalence of polyps and cancer in colonic regions containing diverticula.

METHODS

Six hundred consecutive colonoscopy reports from a single endoscopist were reviewed to determine prevalence and location of diverticulosis and polyps. Additionally, pathology reports of 88 colon cancer resection specimens were reviewed for the presence of diverticulosis, and compared with expected prevalence of diverticulosis in that colonic region based on the collected colonoscopy data.

RESULTS

Overall, rates of detected polyps were comparable between patients with and without diverticulosis. However, analyzing the data by colonic segment containing diverticulosis, the prevalence of adenomatous polyps was reduced in regions of diverticulosis compared to the same colonic segment unaffected by diverticulosis (7 vs. 17% for rectosigmoid (p = 0.005); 5 vs. 18% for descending (p < 0.0001); and 17 vs. 27% for ascending colon (p = 0.0495)). Among colon cancer resection specimens, the prevalence of diverticulosis was significantly reduced in the rectosigmoid and ascending colon, compared with expected rates of diverticulosis in those regions. (13 vs. 42% in rectosigmoid (p = 0.0006); 3 vs. 17% in ascending colon (p = 0.043)).

CONCLUSION

Despite similar overall frequency of polyps in patients with and without diverticulosis, polyps were significantly less likely in the colonic segment affected by diverticulosis. Additionally, the frequency of diverticulosis in areas of cancer in the rectosigmoid and ascending colon was significantly lower than expected compared with the expected frequency of diverticulosis for those colonic regions. These observations suggest a true negative association between colonic neoplasia and diverticulosis.

Prevalence and distribution of colonic diverticula assessed with CT colonography (CTC)

OBJECTIVES

This study aimed to evaluate the prevalence of colonic diverticula according to age, gender, distribution, disease extension and symptoms with CT colonography (CTC).

METHODS

The study population included 1091 consecutive patients who underwent CTC. Patients with diverticula were retrospectively stratified according to age, gender, clinical symptoms and colonic segment involvement. Extension of colonic diverticula was evaluated using a three-point quantitative scale. Using this data, a multivariate regression analysis was applied to investigate the existence of any correlation among variables.

RESULTS

Colonic diverticula were observed in 561 patients (240 men, mean age 68 ± 12 years). Symptomatic uncomplicated diverticular disease (SUDD) was present in 47.4% of cases. In 25.6% of patients ≤40 years, at least one diverticulum in the colon was observed. Prevalence of right-sided diverticula in patients >60 years was 14.2% in caecum and 18.5% in ascending colon. No significant difference was found between symptomatic and asymptomatic patients regarding diverticula prevalence and extension. No correlation was present between diverticula extension and symptoms.

CONCLUSION

The incidence of colonic diverticula appears to be greater than expected. Right colon diverticula do not appear to be an uncommon finding, with their prevalence increasing with patient age. SUDD does not seem to be related to diverticula distribution and extension.

KEY POINTS

Incidence of colonic diverticula appears to be greater than expected. Right colon diverticula do not appear to be an uncommon finding. SUDD does not seem to be related to diverticula distribution and extension.

Increased Risk of Pyogenic Liver Abscess Among Patients With Colonic Diverticular Diseases: A Nationwide Cohort Study

Whether patients with diverticular diseases exhibit a higher risk of developing pyogenic liver abscess (PLA) remains inconclusive.From the inpatient claims in Taiwan's National Health Insurance Research Database, we identified 54,147 patients diagnosed with diverticulosis in the 1998 to 2010 period and 216,588 controls without the disorder. The 2 cohorts were matched by age, sex, and admission year, and were followed up until the end of 2010 to estimate the risk of PLA.Overall, the incidence of PLA was 2.44-fold higher in the diverticular-disease group than in the controls (11.5 vs 4.65 per 10,000 person-year). The adjusted hazard ratio (aHR) of PLA was 2.11 (95% confidence interval [CI], 1.81-2.44) for the diverticular-disease group, according to a multivariate Cox proportional hazards regression model. The age-specific data showed that the aHR for the diverticular-disease group, compared with the controls, was the highest inpatients younger than 50 years old (aHR, 4.03; 95% CI, 2.77-5.85). Further analysis showed that the diverticular-disease group exhibited an elevated risk of PLA regardless of whether patients had diverticulitis.The patients with diverticular diseases exhibited a higher risk of PLA.

Small Intestinal Bacterial Overgrowth Diagnosed by Glucose Hydrogen Breath Test in Post-cholecystectomy Patients

BACKGROUND/AIMS

Patients undergoing cholecystectomy may have small intestinal bacterial overgrowth (SIBO). We investigated the prevalence and characteristics of SIBO in patients with intestinal symptoms following cholecystectomy.

METHODS

Sixty-two patients following cholecystectomy, 145 with functional gastrointestinal diseases (FGIDs), and 30 healthy controls undergoing hydrogen (H2)-methane (CH4) glucose breath test (GBT) were included in the study. Before performing GBT, all patients were interrogated using bowel symptom questionnaire. The positivity to GBT indicating the presence of SIBO, gas types and bowel symptoms were surveyed.

RESULTS

Post-cholecystectomy patients more often had SIBO as evidenced by a positive (+) GBT than those with FGID and controls (29/62, 46.8% vs 38/145, 26.2% vs 4/30, 13.3%, respectively; P = 0.010). In the gas types, the GBT (H2) + post-cholecystectomy patients was significantly higher than those in FGIDs patients (P = 0.017). Especially, positivity to fasting GBT (H2) among the GBT (H2)+ post-cholecystectomy patients was high, as diagnosed by elevated fasting H2 level. The GBT+ group had higher symptom scores of significance or tendency in abdominal discomfort, bloating, chest discomfort, early satiety, nausea, and tenesmus than those of the GBT negative group. The status of cholecystectomy was the only significant independent factor for predicting SIBO.

CONCLUSIONS

The SIBO with high levels of baseline H2 might be the important etiologic factor of upper GI symptoms for post-cholecystectomy patients.

Association between Diverticular Disease and Pre-Neoplastic Colorectal Lesions in an Urban African-American Population

BACKGROUND

It is unclear whether there is a shared pathway in the development of diverticular disease (DD) and potentially neoplastic colorectal lesions since both diseases are found in similar age groups and populations.

AIM

To determine the association between DD and colorectal pre-neoplastic lesions in an African-American urban population.

METHODS

Data from 1986 patients who underwent colonoscopy at the Howard University Hospital from January 2012 through December 2012 were analyzed for this study. The presence of diverticula and polyps was recorded using colonoscopy reports. Polyps were further classified into adenoma or hyperplastic polyp based on histopathology reports. Multiple logistic regression was done to analyze the association between DD and colonic lesions.

RESULTS

Of the 1986 study subjects, 1,119 (56%) were females, 35% had DD and 56% had at least one polyp. There was a higher prevalence of polyps (70 vs. 49%; OR = 2.3; 95% CI: 1.9-2.8) and adenoma (43 vs. 25%; OR = 2.0; 95% CI: 1.7-2.5) in the diverticular vs. non-diverticula patients. Among patients who underwent screening colonoscopy, the presence of diverticulosis was associated with increased odds of associated polyps (OR = 9.9; 95% CI: 5.4-16.8) and adenoma (OR = 5.1; 95% CI: 3.4-7.8).

CONCLUSION

Patients with DD are more likely to harbor colorectal lesions. These findings call for more vigilance on the part of endoscopists during colonoscopy in patients known to harbor colonic diverticula.

Surgical management of colonic diverticular disease: Discrepancy between right- and left-sided diseases

AIM: To compare the outcome of the surgical management of left-sided and right-sided diverticular disease.

METHODS: The medical records of 77 patients who were surgically treated for diverticular disease between 1999 and 2010 in a tertiary referral hospital were retrospectively reviewed. The study population was limited to cases wherein the surgical specimen was confirmed as diverticulosis by pathology. Right-sided diverticula were classified as those arising from the cecum, ascending colon, and transverse colon, and those from the descending colon, sigmoid colon, and rectum were classified as left-sided diverticulosis. To assess the changing trend of occurrence of diverticulosis, data were compared with two previous studies of 51 patients.

RESULTS: The proportion of left-sided disease cases was significantly increased compared to the results of our previous studies in 1994 and 2001, (27.5% vs 48.1%, P < 0.05). Moreover, no differences in gender, body mass index, multiplicity of the diverticula, fever, or leukocytosis were noted between patients with right-sided and left-sided disease. However, patients with right-sided disease were significantly younger (50.9 year vs 64.0 year, P < 0.01). Furthermore, left-sided disease was significantly associated with a higher incidence of complicated diverticulitis (89.2% vs 57.5%, P < 0.01), combined resection due to extensive inflammation (21.6% vs 5.0%, P < 0.05), operative complications (51.4% vs 27.5%, P < 0.05), and in-hospital mortality (10.8% vs 0%, P < 0.05), along with longer post-operative hospitalization duration (21.3 ± 10.2 d vs 10.6 ± 8.1 d, P < 0.05).

CONCLUSION: Compared with right-sided diverticular disease, the incidence of left-sided disease in Korea has increased since 2001 and is associated with worse surgical outcomes.

Surgical management of colonic diverticular disease: discrepancy between right- and left-sided diseases

AIM

To compare the outcome of the surgical management of left-sided and right-sided diverticular disease.

METHODS

The medical records of 77 patients who were surgically treated for diverticular disease between 1999 and 2010 in a tertiary referral hospital were retrospectively reviewed. The study population was limited to cases wherein the surgical specimen was confirmed as diverticulosis by pathology. Right-sided diverticula were classified as those arising from the cecum, ascending colon, and transverse colon, and those from the descending colon, sigmoid colon, and rectum were classified as left-sided diverticulosis. To assess the changing trend of occurrence of diverticulosis, data were compared with two previous studies of 51 patients.

RESULTS

The proportion of left-sided disease cases was significantly increased compared to the results of our previous studies in 1994 and 2001, (27.5% vs 48.1%, P < 0.05). Moreover, no differences in gender, body mass index, multiplicity of the diverticula, fever, or leukocytosis were noted between patients with right-sided and left-sided disease. However, patients with right-sided disease were significantly younger (50.9 year vs 64.0 year, P < 0.01). Furthermore, left-sided disease was significantly associated with a higher incidence of complicated diverticulitis (89.2% vs 57.5%, P < 0.01), combined resection due to extensive inflammation (21.6% vs 5.0%, P < 0.05), operative complications (51.4% vs 27.5%, P < 0.05), and in-hospital mortality (10.8% vs 0%, P < 0.05), along with longer post-operative hospitalization duration (21.3 ± 10.2 d vs 10.6 ± 8.1 d, P < 0.05).

CONCLUSION

Compared with right-sided diverticular disease, the incidence of left-sided disease in Korea has increased since 2001 and is associated with worse surgical outcomes.

Association between colonic diverticulosis and prevalence of colorectal polyps

INTRODUCTION

Diverticulosis and colorectal polyps increase in frequency as the population ages. Proposed common mechanisms for both include lack of dietary fiber, increased saturated fats, and slow colonic transit time. The association of diverticulosis and colorectal polyps has been previously reported with conflicting results. Despite sharing common epidemiologic predisposing factors, the association between diverticulosis and colon polyps remains unclear and needs better clarification.

AIM

The primary aim of our study is to evaluate if there is any association between diverticular disease and colorectal polyps.

MATERIALS AND METHODS

This is a retrospective cohort study. All consecutive patients who underwent colonoscopy between January 2009 and December 2011 were included, except those with history of inflammatory bowel disease, polyposis syndrome, and poor bowel preparation. Univariate and multivariate logistic regression analysis was conducted to analyze the association between colon polyps and diverticulosis. Hyperplastic polyps were excluded from the statistical analysis, and only pre-cancerous adenomas were included.

RESULTS

A total of 2,223 patients met the inclusion criteria. The prevalence of colorectal polyps in patients with diverticulosis was significantly higher than those without diverticulosis (odds ratio (OR) 1.54; 95 % confidence interval (CI) 1.27-1.80, p = 0.001). This association was found significant for all locations of polyps and all histological subtypes. There was also a statistically significant association between age, presence of diverticulosis, and colorectal polyps (OR 1.03; 95 % CI 1.02-1.04). The incidence of colorectal polyps increases as age advances in patients with diverticulosis, with the highest association in patients >70 years of age (OR 3.55; 95 % CI 2.50-5.04). There was no significant association between indication for colonoscopy and presence of colorectal polyps in patients with diverticulosis (OR 0.98; 95 % CI 0.95-1.01). The incidence of diverticulitis was low (<1 %), and there was no association between diverticulitis and colon polyps.

CONCLUSION

There is a significant association between diverticulosis and synchronous pre-cancerous colorectal polyps (adenomas). Patients with diverticulosis have a higher risk of colorectal polyps as compared to those without. This observation needs further validation by a large prospective cohort study.

Breath methane positivity is more common and higher in patients with objectively proven delayed transit constipation

OBJECTIVES

Methane (CH4)-producing intestinal bacteria might be related to constipation. This study was carried out to evaluate the association between breath CH4, colonic transit, and anorectal pressure in constipated patients.

METHODS

A database of consecutive 62 constipated patients fulfilling the Rome III with the lactulose CH4 breath test (LMBT), a colon marker study, and anorectal manometry was studied. The profile of LMBT in patients was compared with 49 healthy controls. The positivity to LMBT (LMBT+) was defined as CH4 of at least 10 ppm in baseline or above baseline within 90 min. There were two types of constipation: normal and delayed transit.

RESULTS

There were significant differences in the breath CH4 between patients with delayed transit and (a) normal transit from 0 to 135 min or (b) healthy controls from 0 to 180 min. The LMBT+ was higher in delayed transit patients than in healthy controls (58.8 vs.12.2%) or in normal transit patients (vs. 13.3%), respectively (P<0.01). The delayed transit was the only independent factor for LMBT+ [odds ratio (95% confidence interval), 27.8 (3.32-250.00), P<0.01]. The left and total colonic transit time were significantly increased in LMBT-positive than in LMBT-negative patients. Significant correlations were found between total CH4 and the time of left or total colonic transit. However, no difference was found in the parameters of manometry by LMBT status.

CONCLUSION

A positive breath CH4 was associated with delayed colonic transit and left colon, and it could be a new therapeutic target for the management of constipated patients with delayed colonic transit.

The characteristics of the positivity to the lactulose breath test in patients with abdominal bloating

OBJECTIVES

The clinical utility in patients with bloating is still conflicting. We aimed to evaluate the positivity to lactulose breath test (LBT) in patients with bloating, and to assess the clinical characteristics according to the positivity or subtypes of LBT.

METHODS

The patients with abdominal bloating undergoing LBT were investigated. Rome III positive irritable bowel syndrome (IBS) and bowel symptoms were surveyed according to the positivity or subtypes of LBT.

RESULTS

The prevalence of IBS and the positivity to LBT was 23.8% (86 of 358) and 29.6% (106 of 358), respectively. The positivity to LBT and the prevalence in subtypes of LBT were not different according to the presence of IBS. The subtypes of LBT positive (+) patients were LBT (H₂) with 61 (57.5%), (CH₄)+ with 30 (28.3%), and (both) positive with 15 (14.2%). The LBT (H₂)+ group was younger, and had higher symptomatic score for the bloating than that in the LBT negative (-) group. The LBT (CH₄)+ group was older, and had higher scores of hard stool and strain than those of the LBT (-) group. In the fasting LBT (H₂)+ group (n=37) diagnosed by increased baseline H₂, the scores for abdominal discomfort, bloating, and flatus were higher than those for the LBT (H₂)+ or LBT(-) groups.

CONCLUSIONS

The subtypes of the positivity to LBT according to the gas produced or the fasting H₂ may contribute to specificity or severity of abdominal symptoms regardless of the presence of IBS.