A novel APC mutation associated with Gardner syndrome in a Chinese family.

Gardner syndrome (GS) is a specific form of familial adenomatous polyposis (FAP), which manifests as colorectal polyps, multiple osteomas and soft tissue tumors, and in the oral cavity as osteomas of the jaws, odontomas, and abnormal tooth counts. The underlying cause of GS is attributed to mutations in the APC gene. Mutations in this gene disrupt the normal functioning of the protein and lead to the development of GS. To further investigate GS, a family affected by the syndrome was selected from Dongguan, Guangdong Province. The family members underwent a comprehensive survey, which involved collecting clinical data and peripheral venous blood samples. The samples were then used for genetic analysis. Whole exome sequencing (WES) and Sanger sequencing techniques were utilized to screen and identify specific mutation sites in the APC gene. The clinical findings for the GS family included the presence of gastrointestinal polyps and odontomas. After analyzing the genetic sequencing results, a novel mutation site c.4266dupA on the APC gene was found in the patients, which leading to the APC protein truncation. As a result of this study, it is suggested that odontoma may be an early indicator of GS. Additionally, the identification of this novel mutation site in the APC gene expands the known spectrum of genetic mutations associated with the disease. This discovery has significant implications for the early diagnosis of GS, thus enabling timely intervention to reduce the risk of developing colon cancer and other related diseases.

The p300/YY1/miR-500a-5p/HDAC2 signalling axis regulates cell proliferation in human colorectal cancer.

The biological role of miR-500a-5p has not yet been reported in the context of colorectal cancer (CRC). Here, we show that miR-500a-5p expression is decreased in CRC tissues compared with adjacent normal tissues. Low miR-500a-5p expression is associated with malignant progression. Moreover, transfection of CRC cells with miR-500a-5p induces G0/G1 cell cycle arrest and inhibits their growth and migration. Mechanistically, miR-500a-5p directly targets HDAC2 and inhibits HDAC2-mediated proliferation in CRC in nude mice. Furthermore, YY1 binds to the promoter of miR-500a-5p and negatively regulates its transcription. Restoration of miR-500a-5p expression is up-regulated via the p300/YY1/HDAC2 complex. Besides, therapeutic delivery of miR-500a-5p significantly suppresses tumour development in a xenograft tumour model and a HDAC2 inhibitor FK228-treated CRC model. Our studies demonstrate that miR-500a-5p functions as a tumour suppressor in CRC by targeting the p300/YY1/HDAC2 axis, which contributes to the development of and provides new potential candidates for CRC therapy.

Decreased CD8+CD28+/CD8+CD28- T cell ratio can sensitively predict poor outcome for patients with complicated Crohn disease.

Crohn disease (CD) with complications such as penetrating, stricturing, and perianal disease is called complicated CD. The aim of this study is to test the efficiency with which the CD8CD28/CD8CD28 cell balance can predict a subsequent active stage in patients with newly diagnosed complicated CD.Seventeen patients with complicated CD and 48 CD patients with no complications were enrolled. Blood CD8 T cells were tested from all of the 65 newly diagnosed CD patients upon enrollment. The potential risk factors were compared between the 2 groups. A 30-week follow-up was performed, and the efficiency of the CD8 cell balance at predicting active CD was analyzed using receiver-operating characteristic curves. The cumulative remission lasting rates (CRLRs) were analyzed using the Kaplan-Meier method.Compared with the control CD group, patients with complicated CD were predominantly male and younger in age; they also had lower body mass indices (BMIs), higher Crohn disease activity indices (CDAIs), higher immunosuppressant and steroid prescription rates, and significantly higher surgical rates. The CD8CD28/CD8CD28 balance was associated with BMI, CDAI, steroids, and surgery. The CD8CD28/CD8CD28 ratios were significantly lower at week 0 and on the 6th, 22nd, and 30th week during follow-up with a shorter lasting time of remission for the complicated CD patients. The CD8CD28/CD8CD28 ratio could accurately predict the active stage for the patients with complicated CD, and the highest sensitivity (89.2%) and specificity (85.3%) were found when the ratio was 1.03. Treatment with steroids and surgery, along with a significantly lower CD8CD28/CD8CD28 ratio and lower CRLRs, was closely related to a worse outcome for the patients with complicated CD.Patients requiring steroids and surgery experience more severe disease activity and thus a disequilibrated immunological balance, which could be the main reason for a decreased CD8CD28/CD8CD28 ratio. This ratio can sensitively predict the active stage for patients with complicated CD, and more care should be taken when this ratio is <1.03.

CD8+CD28+/CD8+CD28- T cell equilibrium can predict the active stage for patients with inflammatory bowel disease.

BACKGROUND/AIM: The balance of blood CD8+CD28+/CD8+CD28- T cells has been verified to be vital for patients with ulcerative colitis (UC), but their role in inflammatory bowel disease (IBD) remains unknown. This investigation aimed to evaluate the efficiency of the balance in predicting the active stage in IBD patients. METHODS: Fifty-three IBD subjects, including 31 UC and 22 Crohn's disease (CD) patients, were enrolled, and their peripheral blood CD8+CD28+ and CD8+CD28- T cell levels were tested using flow cytometry. The risk factors related to prognosis were compared between UC and CD patients. A 1-year follow-up was performed for all the IBD patients, and the CD8+ T cells and their ratio were compared at the 3rd, 6th, 9th, and 12th months during follow-up. The sensitivity and specificity of the CD8+ T cell level and balance were analyzed through receiver operator characteristic (ROC) curves. The cumulative remission lasting rates (CRLRs) under the different factors were analyzed using the Kaplan-Meier method. RESULTS: Higher prescription rates of immunosuppressants, steroids, probiotics, and biological agents (BAs) were found in CD subjects in comparison to UC subjects (P=0.005, 0.024, 0.034, and 0.001), as was a higher active rate during follow-up (95.5% of CD patients vs 67.7% of UC patients, P=0.035). The CD8+CD28+ T cell level and the CD8+CD28+/CD8+CD28- T cell ratio were significantly higher in UC patients than in CD patients, but the reverse was true for CD8+CD28- T cells during follow-up at the 9th and 12th month (all P<0.05). The diagnostic models of the initial CD8+CD28+ and CD8+CD28- T cell numbers and the CD8+CD28+/CD8+CD28- T cell ratio in predicting the active stage were found to be significant, with areas under the curves (AUCs) of 0.883, 0.098, and 0.913 for UC subjects (with 95% CI: 0.709-0.940, 0.009-0.188, and 0.842-1.003; P=0.001, 0.00, and 0.000) and 0.812, 0.078, and 0.898 for CD subjects (with 95% CI: 0.683-0.957, 0.003-0.158, and 0.837-0.998; P=0.003, 0.00, and 0.000). The cut-off values showed that when the ratios were 1.30 for UC and 1.22 for CD patients, the best sensitivity and specificity were observed, with 91.6% and 89.0% for UC and 88.5% and 85.1% for CD, respectively. The CRLRs were significantly higher in female, non-BA-treated, non-surgical IBD subjects when compared to male, BA-treated, surgical subjects (P=0.031, 0.000, and 0.000). The number of CD8+CD28+ and CD8+CD28- T cells and the CD8+CD28+/CD8+CD28- T cell ratio were correlated with BA treatment and surgery (all P<0.05). CONCLUSION: The CD8+CD28+/CD8+CD28- T cell balance, expected to be a novel immunologic marker, presented a satisfactory efficiency with high sensitivity and specificity in predicting the active stage in UC and CD patients, and the balance was closely related to the use of BAs and surgery.

Annonaceous acetogenins mediated up-regulation of Notch2 exerts growth inhibition in human gastric cancer cells in vitro.

BACKGROUND: Gastric cancer (GC) is a global health problem because of limited treatments and poor prognosis. Annonaceous acetogenins (ACGs) has been reported to exert anti-tumorigenic effects in cancer, yet the mechanism underlying its effects on GC remains largely unknown. Notch signaling plays a critical role in cell proliferation, differentiation and apoptosis. Therefore, it may contribute to the development of GC. This study aims to explore the role of Notch2 in ACGs' activities in GC cells. RESULTS: ACGs inhibited GC cells' viability in a dose dependent manner and led to cell apoptosis and cell cycle arrest in G0/G1 phase with an increased Notch2 expression. Additionally, Notch2 siRNA reduced ACGs-induced cell growth inhibition while Notch2 cDNA transfection did the opposite. MATERIALS AND METHODS: ACGs were administrated in GC cells and cell proliferation was assayed by MTS, cell apoptosis and cell cycle were detected by flow cytometry. Additionally, the expression of Notch2 and the downstream target Hes1 were identified by Western blot. Furthermore, Notch2-siRNA transfection and Notch2-cDNA were performed to investigate the role of Notch2 in the antitumor effect of ACGs. CONCLUSIONS: Up-regulation of Notch2 by ACGs is a potential therapeutic strategy for GC.

Maneuverability and safety of a magnetic-controlled capsule endoscopy system to examine the human colon under real-time monitoring by colonoscopy: a pilot study (with video).

BACKGROUND AND AIMS: Colon capsule endoscopy has become an alternative method to evaluate the colonic mucosa without pain, sedation, and gas insufflation in recent years. The magnetic-controlled capsule endoscopy (MCCE) system is an innovative ingestible colon capsule. We performed a pilot study to assess its maneuverability and safety among subjects who volunteered to undergo colorectal cancer screening. METHODS: Fifty-seven volunteers underwent both MCCE and colonoscopy procedures. The position of the MCCE was monitored after the capsule was swallowed. When the MCCE reached the cecum, it was controlled by a magnetic manipulator to observe the colonic mucosa under real-time monitoring by colonoscopy. The primary measurements included maneuverability, the level of cleanliness, lesions, and safety. RESULTS: Five volunteers (8.78%) were excluded because of bowel preparation protocol deviations or failure to reach the cecum before the battery was exhausted. There was no capsule retention. Maneuverability of the MCCE to match the guidance of the magnetic manipulator was graded as good in 49 subjects (94.23%) and moderate in 3 (5.77%). It took 3.63 ± 1.14 hours for the MCCE to reach the cecum. In 52 subjects (100%) the MCCE reached the transverse colon positively, and in 41 subjects (78.84%) the MCCE reached the rectosigmoid colon within a limited time of 25 minutes. The bowel preparation for MCCE was rated as good or excellent in 84.61% of the volunteers. Six positive findings were identified by the MCCE in the colon, which were also confirmed by colonoscopy. CONCLUSIONS: The MCCE showed promising maneuverability under real-time monitoring by colonoscopy. (Clinical trial registration number: NCT02536144.).

Disequilibrium in the CD8+CD28+/CD8+CD28- T Lymphocyte Balance Is Related to Prognosis in Rats with Trinitrobenzenesulfonic Acid-Induced Colitis.

PURPOSE: The CD8+CD28+/CD8+CD28- T lymphocyte balance is vital for human ulcerative colitis (UC) but has not been defined in experimental colitis. This investigation will try to identify the changes that occur in the CD8+CD28+/CD8+CD28- T lymphocyte balance during the progression of trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats. METHODS: The frequencies of blood CD8+CD28+ and CD8+CD28- T lymphocytes were detected in the rats belonging to the normal, model, and treated groups on five days using flow cytometry. The treated rats were administered with mesalazine and were euthanized after a 14-day treatment, as were the normal and model rats. The sensitivity and specificity of the CD8+CD28+/CD8+CD28- T lymphocyte balance in diagnosing early colitis were analyzed by receiver operating characteristics (ROC) curves. The frequencies of CD8+CD28+ and CD8+CD28- T lymphocytes in the colon tissue were tested via immunofluorescence. ELISA was used to measure the levels of the cytokines. Immunohistochemistry and Western blotting were used to detect the colonic expression of JAK3, STAT6, NFATc2, and GATA3. RESULTS: We found that the ratio of CD8+CD28+/CD8+CD28- T lymphocytes decreased, as did the level of interleukin-7, but not IL-12p40, IL-13, or IL-15, in the blood; however, the ratio increased along with JAK3, STAT6, NFATc2, and GATA3 in the colon of the rats with colitis. The changes were effectively reversed through the administration of mesalazine for 13 days. Surprisingly, the balance in the blood could sensitively distinguish rats with early colitis from normal rats. CONCLUSION: These data show that increase in CD8+CD28+ T cells in blood and decrease in CD8+CD28- T cells in colon are associated with experimental colitis.

[Immunological balance of CD8+CD28+/CD8+CD28- T lymphocytes can predict gastrointestinal hemorrhage in patients with inflammatory bowel disease].

OBJECTIVE: To evaluate the sensitivity and specificity of CD8+CD28+/CD8+CD28- T lymphocyte balance in predicting the gastrointestinal hemorrhage (GH) in patients with inflammatory bowel disease (IBD). METHODS: Forty-nine IBD patients, including 30 with ulcerous colitis (UC) and 19 with Crohn's disease (CD), were enrolled to test peripheral blood CD8+CD28+ and CD8+CD28- T cells using flow cytometry. All the patients were followed up for one year. The receiver-operating characteristic (ROC) curves were used to test the efficiency of CD8+CD28+/CD8+CD28- T lymphocyte balance to predict GH. The differences in lasting time of remission (LTR) under different factors were compared using Kaplan-Meier survival analysis, and the correlation between CD8+ T lymphocytes and the factors were analyzed. RESULTS: The utilization rates of immunosuppressant, steroids, and biological agent (BA) were significantly higher in CD patients than in UC patients (P=0.003, 0.043 and 0.002, respectively). The frequencies of CD8+CD28+T cells were obviously higher in UC patients than those in CD patients (t=3.022, P=0.004). CD8+CD28+T cells, CD8+CD28- T cells, and especially CD8+CD28+/CD8+CD28- ratio (area under curve of 0.977, P=0.000; cut-off value of 1.14 [13.95%/12.24%] with a sensitivity of 93.3% and a specificity of 91.2%) showed good efficiencies in predicting GH (P<0.01). The mean and median of LTR of IBD patients who did not receive BA or surgical treatment were significantly longer (Χ2=9.730, P=0.002; Χ2=15.981, P=0.000). CD8+CD28+/CD8+CD28- ratio was significantly related to both BA (P=0.009) and surgery (P=0.038). CONCLUSION: Both decreased CD8+CD28+T cells and elevated CD8+CD28-T cells are closely correlated with GH, and their ratio can predict the occurrence of GH with a high sensitivity and specificity and is correlated with BA and surgery at the cut-off value of 1.14.

Involvement of Activated Cdc42 Kinase1 in Colitis and Colorectal Neoplasms.

BACKGROUND Activated Cdc42 kinase1 (ACK1) is a non-receptor tyrosine kinase which is critical for cell survival, proliferation, and migration. Genomic amplification of ACK1 has been reported in multiple human cancers. We aimed to investigate ACK1 protein expression in colorectal mucosa with inflammation and neoplasm, and to evaluate its correlation with disease activity and severity. MATERIAL AND METHODS A total of 250 individuals who underwent total colonoscopy were collected randomly from January 2007 to May 2013 in Nanfang Hospital, Guangzhou, China. Colorectal mucosal biopsy specimens were obtained by endoscopy from 78 patients with ulcerative colitis (UC), 22 with Crohn's disease (CD), 20 with infectious colitis, 26 with non-IBD and noninfectious colitis, 16 with sporadic adenomas, 4 with dysplasia-associated lesions or masses, 10 with sporadic colorectal cancer (CRC), 4 with UC-related CRC, 10 with hyperplastic polyps, and 60 without colonic abnormalities. ACK1 protein levels were determined immunohistochemically. The correlations of ACK1 expression with disease activity and severity were also evaluated. RESULTS Significantly increased ACK1 expression was observed in epithelial cells of colorectal mucosa with inflammation and dysplasia compared to controls (P<0.05). ACK1 expression correlated with clinical activity in IBD (χ²=4.57, P=0.033 for UC; χ²=5.68, P=0.017 for CD), as well as grade of dysplasia in preneoplastic lesions (P<0.05). No significant differences in ACK1 expression were found between UC and CD, or between IBD and non-IBD conditions (P>0.05). CONCLUSIONS ACK1 protein is increased extensively in colitis and colorectal dysplasia. ACK1 overexpression may play a role in colorectal inflammation and neoplasms.

Clinical implications of PTEN and VEGF expression status, as well as microvessel density in esophageal squamous cell carcinoma.

There are limitations to the use of single biomarker levels, for example phosphate and tensin homology (PTEN) or vascular endothelial growth factor (VEGF), in the diagnosis of esophageal squamous cell carcinoma (ESCC). The present study therefore aimed to evaluate the clinical implications of combined detection of multiple biomarkers. The associations between PTEN and VEGF expression status, microvessel density (MVD), and the pathological characteristics of 50 patients with ESCC were determined using χ2, analysis of variance, and t-tests. The results indicated that the PTEN-positive rate was negatively correlated with ESCC histological grade (P<0.01), depth of ESCC invasion (P<0.01) and lymph node metastasis status. Furthermore, the VEGF-positive rate was correlated with lymph node metastasis status, while MVD was correlated with the depth of ESCC invasion (P<0.01) and lymph node metastasis status (P<0.05). The PTEN-positive rate was negatively correlated with the VEGF-positive rate. A higher MVD was identified in ESCC samples than that of the normal esophageal mucosa, particularly in VEGF-positive ESCC specimens compared with those of VEGF-negative specimens, and PTEN-negative ESCC specimens compared with that of the PTEN-positive ESCC specimens. These results suggested that combined detection of PTEN and VEGF levels, as well as evaluation of MVD in patients with ESCC may provide essential information for improvements in the diagnosis and prognosis of ESCC.

A Preliminary Comparison of Endoscopic Sphincterotomy, Endoscopic Papillary Large Balloon Dilation, and Combination of the Two in Endoscopic Choledocholithiasis Treatment.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is commonly performed to remove bile duct stones. Endoscopic sphincterotomy (EST), endoscopic papillary large balloon dilation (EPLBD), and endoscopic sphincterotomy plus large balloon dilation (ESLBD) are 3 methods used to enlarge the papillary orifice, but their efficacy and safety remains controversial. This study aimed to compare these methods for treating common bile duct (CBD) stones. MATERIAL AND METHODS: Between July 2011 and December 2013, 255 consecutive patients with proven CBD stones were randomly assigned to EST, EPLBD, or ESLBD (n=85/group). The stone clearance rate, cannulation time, procedural time, frequency of mechanical lithotripsy (ML) use, complications, mortality, and procedural costs were compared. RESULTS: A total of 92.9%, 91.8%, and 96.5% of the patients in the EST, EPBD, and ESBD groups had stones cleared at first ERCP (P=0.519), respectively. ML was used in 9.4%, 14.1%, and 8.2% of the patients in the EST, EPLBD, and ESLBD groups (P=0.419). The costs of EPLBD were higher than EST and lower than ESLBD (P<0.001). Complications occurred in 4.7%, 4.7%, and 5.9% of the patients in the EST, EPLBD, and ESLBD groups, respectively (P=1.000). The proportion in severity was similar (P=0.693). None of the patients died after the procedures. The rates of the post-ERCP pancreatitis, cholangitis, and bleeding were similar among all groups. CONCLUSIONS: EST, EPLBD, and ESLBD might clear CBD stones with equal efficacy and safety. A non-inferiority trial might be necessary to confirm these results.

ZNF703 acts as an oncogene that promotes progression in gastric cancer.

ZNF703, a member of the NET/Nlz family of zinc finger transcription factors, contributes to aspects of developmental growth and patterning across evolutionarily diverse species. ZNF703 has been identified as a novel oncogene in human breast cancer. In the present study, we investigated the expression of ZNF703 in gastric carcinoma and attempted to determine, using cell line models, its biological actions. Using immunohistochemistry, we analyzed the ZNF703 protein expression in 120 clinicopathologically characterized gastric cancer cases. Using RNA interference, we investigated the effects of ZNF703 depletion on tumor proliferation and metastasis in vitro. We found that ZNF703 was overexpressed in invasive gastric carcinoma tissues, and its expression levels were closely correlated with the depth of invasion, node metastasis and venous invasion. RNA interference-mediated silencing of the ZNF703 gene in SGC7901 cells inhibited cell proliferation and migration significantly. The results showed that ZNF703 acts as a gastric cancer oncogene and should be considered a therapeutic target for metastatic gastric cancer.

Double-balloon enteroscopy for mesenchymal tumors of small bowel: nine years' experience.

AIM: To assess the value of double-balloon enteroscopy (DBE) for the diagnosis of gastrointestinal mesenchymal tumors (GIMTs) in the small bowel and clarify their clinical and endoscopic characteristics. METHODS: A retrospective review in a total of 783 patients who underwent a DBE procedure from January 2003 to December 2011 was conducted. Data from patients with pathologically confirmed GIMTs were analyzed at a single tertiary center with nine years' experience. The primary outcomes assessed included characteristics of patients with GIMTs, indications for DBE, overall diagnostic yield of GIMTs, endoscopic morphology, positive biopsy, comparison of diagnosis with capsule endoscopy, and subsequent interventional management. RESULTS: GIMTs were identified and analyzed in 77 patients. The mean age was 47.74 ± 14.14 years (range: 20-77 years), with 63.6% being males. The majority of individuals presented with gastrointestinal bleeding, accounting for 81.8%, followed by abdominal pain, accounting for 10.4%. Small bowel pathologies were found in 71 patients, the detection rate was 92.2%. The diagnostic yield of DBE for GIMTs was 88.3%. DBE was superior to capsule endoscopy in the diagnosis of GIMTs (P = 0.006; McNemar's χ(2) test). Gastrointestinal stromal tumor was the most frequent and leiomyoma was the second frequent GIMT. Single and focal lesions were typical of GIMTs, and masses with smooth or unsmooth surface were the most common in the small bowel. GIMTs were removed from all the patients surgically except one patient treated with endoscopic resection. CONCLUSION: DBE is a safe and valuable procedure for patients with suspected GIMTs, and it provides an accurate position for subsequent surgical intervention.

Microscopic colitis in patients with chronic diarrhea and normal colonoscopic findings in Southern China.

BACKGROUND AND OBJECTIVES: Microscopic colitis includes lymphocytic colitis and collagenous colitis. The entity is considered as an important cause for unknown chronic diarrhea, but rarely reported in China before. This study aimed to determine the prevalence of microscopic colitis in patients with chronic diarrhea and normal colonoscopy findings in Southern China, and to reveal the clinical feature of microscopic colitis in these patients. METHODS: Patients with chronic diarrhea and normal colonoscopic findings were enrolled from three hospitals in Southern China from January, 2009 to June, 2010. Multiple colorectal biopsies were obtained in these patients and histological examination was underwent with hematoxyin and eosin stain, Masson's trichrome stain and immunohistochemistry for tenascin to screen lymphocytic colitis and collagenous colitis. The clinical symptom and risk factor of microscopic colitis were assessed by comparing with controls. The diagnostic overlap between microscopic colitis and irritable bowel syndrome or functional diarrhea was also analyzed. RESULTS: Randomly mucosal biopsies were performed in 613 patients with chronic diarrhea and normal or near normal colonoscopic finding. Fifty-nine cases of lymphocytic colitis and 28 cases of collagenous colitis were found by histological examination. The rates of rheumatoid arthritis in lymphocytic colitis group (15.4 %) and collagenous colitis group (14.3 %) were significant higher than in control group (2.2 %). Rheumatoid arthritis was confirmed as the risk factor of microscopic colitis by logistic regression analysis. There was no difference on the symptoms among the controls, patients with lymphocytic colitis, and patients with collagenous colitis. There were 13.8 % (12/87) of patients with microscopic colitis fulfilled Rome III criteria of irritable bowel syndrome and 42.5 % (37/87) fulfilled the criteria of functional diarrhea. CONCLUSIONS: Microscopic colitis is not an uncommon disorder in Chinese population. Rheumatoid arthritis is the risk factor of microscopic colitis. Microscopic colitis has a symptomatic overlap with irritable bowel syndrome and functional diarrhea. It is reasonable to obtain multiple biopsies in patients with chronic diarrhea when the mucosa grossly normal at colonoscopy.

Organic colonic lesions in 3,332 patients with suspected irritable bowel syndrome and lacking warning signs, a retrospective case--control study.

PURPOSE: The diagnosis of irritable bowel syndrome is symptom based, and colonoscopy is the most direct way to rule out organic colonic diseases. It is controversial on the necessity of colonoscopy for patients with suspected irritable bowel syndrome and lacking alarm features. This study was designed to verify the organic lesions and discuss the value of colonoscopy in this type of patients. METHODS: Colonoscopy of 3,332 patients with suspected irritable bowel syndrome and lacking warning signs from 2000 to 2009 were reviewed. One thousand five hundred eighty-eight patients under 50 years of age who underwent colonoscopy screening for health care in the same period were used as controls. The prevalence of different colonic organic lesions was compared between two groups. RESULTS: Organic colonic lesions were found in 30.3% of the patients with suspected irritable bowel syndrome (1,010/3,332) and 39.0% of the controls (619/1,588). Compared with controls, patients with suspected irritable bowel syndrome had higher prevalence of noninflammatory bowel disease and noninfectious colitis and terminal ileitis, however, had lower prevalence of diverticular disease, adenomatous polyps, and non-adenomatous polyps (all P < 0.001). CONCLUSIONS: The diagnostic sensitivity of symptom criteria on irritable bowel syndrome without colonoscopy is not more than 69.7% in patients with suspected irritable bowel syndrome lacking warning signs. Though the method of colonoscopy is hard to screen tumor in this type of patients, it is beneficial to uncover some other relevant organic lesions such as terminal ileitis. Colonoscopy should not be refused to suspected irritable bowel syndrome patients without warning signs.