Colon neoplasia co-existing with coeliac disease in older patients: coincidental,probably; important,certainly

BACKGROUND: Coeliac disease and colorectal neoplasia are both common, present most often in patients over 40 and cause similar symptoms. Greater awareness and early use of serological tests have improved the diagnosis of coeliac disease, but raise the concern that co-existing colorectal neoplasia may be missed. This study assessed the prevalence of colorectal neoplasia among patients with coeliac disease diagnosed after the age of 40 who presented with altered bowel habit or iron deficiency. METHODS: All patients meeting the above criteria underwent colonoscopy unless this or barium enema had been performed shortly before. RESULTS: Of 69 patients with coeliac disease undergoing colonoscopy, 7 (10%) had colon neoplasia: 5 had tubulovillous polyps, and 2 had carcinoma. The prevalence figures for coeliac patients undergoing colonoscopy with iron deficiency and altered bowel habit alone were 11% (5 of 47) and 10% (2 of 22), respectively None of a further 13 who had undergone previous colon investigation (all by barium enema) had neoplasia, although these were probably a selected population. The seven patients with colorectal neoplasia had not reported rectal bleeding. The prevalence of colorectal neoplasia was not significantly higher than in two series of non-coeliac patients undergoing colonoscopy for investigation of iron deficiency (12%) or altered bowel habit (8%). CONCLUSIONS: There is a high prevalence of colorectal neoplasia among older patients with coeliac disease who present with iron deficiency or altered bowel habit, though this is no higher than for non-coeliac patients with these presentations. The possibility of dual pathology should be considered and excluded by colon investigation.     

Colon Neoplasia Co-existing with Coeliac Disease in Older Patients: Coincidental,Probably; Important,Certainly

Background: Coeliac disease and colorectal neoplasia are both common, present most often in patients over 40 and cause similar symptoms. Greater awareness and early use of serological tests have improved the diagnosis of coeliac disease, but raise the concern that co-existing colorectal neoplasia may be missed. This study assessed the prevalence of colorectal neoplasia among patients with coeliac disease diagnosed after the age of 40 who presented with altered bowel habit or iron deficiency. Methods: All patients meeting the above criteria underwent colonoscopy unless this or barium enema had been performed shortly before. Results: Of 69 patients with coeliac disease undergoing colonoscopy, 7 (10%) had colon neoplasia: 5 had tubulovillous polyps, and 2 had carcinoma. The prevalence figures for coeliac patients undergoing colonoscopy with iron deficiency and altered bowel habit alone were 11% (5 of 47) and 10% (2 of 22), respectively None of a further 13 who had undergone previous colon investigation (all by barium enema) had neoplasia, although these were probably a selected population. The seven patients with colorectal neoplasia had not reported rectal bleeding. The prevalence of colorectal neoplasia was not significantly higher than in two series of non-coeliac patients undergoing colonoscopy for investigation of iron deficiency (12%) or altered bowel habit (8%). Conclusions: There is a high prevalence of colorectal neoplasia among older patients with coeliac disease who present with iron deficiency or altered bowel habit, though this is no higher than for non-coeliac patients with these presentations. The possibility of dual pathology should be considered and excluded by colon investigation.     

What does sigmoidoscopy really miss?

The relative effectiveness of flexible sigmoidoscopy compared with colonoscopy to screen for colorectal cancer depends on the magnitude of the association between findings in the proximal and distal colon and the false-negative rate of screening sigmoidoscopy for proximal neoplasia. Lewis et al. performed a systematic review and meta-analysis of screening colonoscopy studies. Published studies through July 31, 2000 of asymptomatic patients undergoing screening colonoscopy were identified from the MEDLINE database. The authors generated pooled estimates of the odds ratio for the association between findings in the distal and proximal colon and the prevalence of isolated proximal adenomatous neoplasia. With the sigmoid–descending colon junction used to identify the beginning of the distal colon, the pooled odds ratio for the association between distal adenomatous polyps and any proximal neoplasia was 2.40 (95% confidence interval [Cl] = 1.42–4.05). Diminutive distal adenomatous polyps were also associated with proximal neoplasia (odds ratio = 2.36; 95% CI = 1.30–4.29). Distal hyperplastic polyps were not associated with proximal neoplasia (odds ratio = 1.44; 95% CI = 0.79–6.62). The prevalence of isolated advanced proximal neoplasia in the three studies was 2%, 3%, and 5%, respectively. When the sigmoid–descending colon junction is used to identify the beginning of the distal colon, this yields a pooled estimate of isolated proximal neoplasia of 16.3% (95% CI = 13.6%–19.1%). Distal adenomatous polyps, including diminutive distal adenomatous polyps, are associated with an increasing prevalence of synchronous proximal neoplasia. From 2% to 5% of patients undergoing screening colonoscopy might have isolated advanced proximal neoplasia.     

Detection of proximal adenomatous polyps with screening sigmoidoscopy: a systematic review and meta-analysis of screening colonoscopy

BACKGROUND: The relative effectiveness of flexible sigmoidoscopy compared with colonoscopy to screen for colorectal cancer depends on the magnitude of the association between findings in the proximal and distal colon and the false-negative rate of screening sigmoidoscopy for proximal neoplasia. To address this, we performed a systematic review and meta-analysis of screening colonoscopy studies. METHODS: Published studies through July 31, 2000, of asymptomatic patients undergoing screening colonoscopy were identified from the MEDLINE database. We generated pooled estimates of the odds ratio for the association between findings in the distal and proximal colon and the prevalence of isolated proximal adenomatous neoplasia. RESULTS: Using the sigmoid-descending colon junction to identify the beginning of the distal colon, the pooled odds ratio for the association between distal adenomatous polyps and any proximal neoplasia was 2.40 (95% confidence interval [CI], 1.42-4.05). Diminutive distal adenomatous polyps were also associated with proximal neoplasia (odds ratio, 2.36; 95% CI, 1.30-4.29). Distal hyperplastic polyps were not associated with proximal neoplasia (odds ratio, 1.44; 95% CI, 0.79-2.62). The prevalence of isolated advanced proximal neoplasia in the 3 studies was 2%, 3%, and 5%. Using the sigmoid-descending colon junction to identify the beginning of the distal colon yields a pooled estimate of isolated proximal neoplasia of 16.3% (95% CI, 13.6%-19.1%). CONCLUSIONS: Distal adenomatous polyps, including diminutive distal adenomatous polyps, are associated with an increased prevalence of synchronous proximal neoplasia. Two percent to 5% of patients undergoing screening colonoscopy may have isolated advanced proximal neoplasia. Even more patients may have isolated nonadvanced proximal neoplasia.     

Microscopic colitis as a missed cause of chronic diarrhea

AIM: To determine the prevalence of increased intraepithelial lymphocytes, using immunohistochemistry in patients with normal colonoscopy and near normal biopsy. METHODS: We retrospectively reviewed all non-malignant colon mucosal biopsies between 2005 and 2007, reported as normal, chronic inflammation or melanosis coli in patients who were undergoing routine colonoscopy. Immunohistochemistry using CD3 was performed on all mucosal biopsies and an intraepithelial lymphocyte count (IEL) was determined. Cases ...     

Rectosigmoid findings are not associated with proximal colon cancer： Analysis of 6 196 consecutive cases undergoing total colonoscopy

AIM: To review the risk of proximal colon cancer in patients undergoing colonoscopy. METHODS: We estimated the risk of advanced proximal adenomas and cancers in 6 196 consecutive patients that underwent colonoscopy (mean age 60 years, 65% males, without prior history of colorectal examination). Neoplasms were classified as diminutive adenoma (5 mm or less), small adenoma (6-9 mm), advanced adenoma (10 mm or more, with villous component or high-grade dysplasia) and cancer (invasive adenocarcinoma). The sites of neoplasms were defined as rectosigmoid (rectum and sigmoid colon) and proximal colon (from cecum to descending colon). RESULTS: The trend of the prevalence of advanced proximal adenoma was to increase with severe rectosigmoid findings, while the prevalence of proximal colon cancer did not increase with severe rectosigmoid findings. Among the 157 patients with proximal colon cancer, 74% had no neoplasm in the rectosigmoid colon. Multivariate logistic-regression analysis revealed that age was the main predictor of proximal colon cancer and existence of rectosigmoid adenoma was not a predictor of proximal colon cancer. CONCLUSION: Sigmoidoscopy is inadequate for colorectal cancer screening, especially in older populations.     

Colonoscopic yield of colorectal neoplasia in daily clinical practice

AIM： To assess the prevalence and location of advanced neoplasia in patients undergoing colonoscopy, and to compare the yield per indication. METHODS： In a multicenter colonoscopy survey （n = 18 hospitals） in the Amsterdam area （Northern Holland）, data of all colonoscopies performed during a three month period in 2005 were analyzed. The location and the histological features of all colonic neoplasia were recorded. The prevalence and the distribution of advanced colorectal neoplasia and differences in yield between indication clusters were evaluated. Advanced neoplasm was defined as adenoma 〉 10 mm in size, with 〉 25% villous features or with high-grade dysplasia or cancer. RESULTS： A total of 4623 eligible patients underwent a total colonoscopy. The prevalence of advanced neoplasia was 13%, with 281 （6%） adenocarcinomas and 342 （7%） advanced adenomas. Sixty-seven percent and 33% of advanced neoplasia were located in the distal and proximal colon, respectively. Of all patients with right-sided advanced neoplasia （n = 228）, 51% had a normal distal colon, whereas 27% had a synchronous distal adenoma. Ten percent of all colonoscopies were performed in asymptomatic patients, 7% of whom had advanced neoplasia. In the respective procedure indication clusters, the prevalence of rightsided advanced neoplasia ranged from 11%-57%. CONCLUSION： One out of every 7-8 colonoscopies yielded an advanced colorectal neoplasm. Colonoscopy is warranted for the evaluation of both symptomatic and asymptomatic patients.     

Ursodeoxycholic acid therapy and the risk of colorectal adenoma in patients with primary biliary cirrhosis: an observational study

Ursodeoxycholic acid (UDCA) is the first-line treatment for primary biliary cirrhosis (PBC). The long-term administration of UDCA might indirectly favor colon carcinogenesis by increasing the fecal excretion of secondary bile acids or, in contrast, it might inhibit colon carcinogenesis, as demonstrated in animal models. In patients with PBC, we examined the effect of prolonged UDCA administration on the prevalence and recurrence of colorectal adenoma and on the proliferation of colon epithelial cells. One hundred fourteen patients (103 women, 11 men; mean age, 55 years) with PBC, were enrolled in a colonoscopic surveillance program. The prevalence of colon adenoma was compared in patients already treated with UDCA (mean duration 46 months) at the time of colonoscopy (treated group, n = 52) and in patients undergoing colonoscopy just prior to treatment initiation (untreated group, n = 62). The recurrence of adenoma following removal (mean follow-up, 35 months) was compared between UDCA-treated patients and appropriate age- and gender-matched controls (2/1) selected from a cohort of 205 patients undergoing polypectomy. Epithelial cell proliferation was assessed using anti-Ki67 antibodies on colon biopsies from both treated and untreated patients. Treated and untreated patients displayed similar demographic characteristics. The prevalence of colorectal adenomas was 13% in the treated group versus 24% in the untreated group (P =.16). The colon epithelial cell proliferation index was significantly lower in treated patients than in untreated patients (P =.001). Following removal of the adenoma, the probability of recurrence was significantly lower in patients treated with UDCA than in controls (7% vs. 28% at 3 years, P =.04). In conclusion, this study suggests that, in patients with PBC, the prolonged administration of UDCA (1) is not associated with an increased prevalence of colorectal adenomas, and (2) significantly decreases the probability of colorectal adenoma recurrence following removal. These results are strengthened by the significant reduction in colon epithelial cell proliferation seen in patients treated with UDCA.     

Synchronous Proximal Polyps and Cancer in Patients with Polyps Detected at Sigmoidoscopy: Results of a Single, Rural-Based Sigmoidoscopy Clinic

The prevalence of polyps and cancer in the proximal colon among patients who have polyps detected on sigmoidoscopy was determined in a large rural referral hospital in north central Pennsylvania. Eleven thousand one hundred sixty patients underwent sigmoidoscopy between 1991 and 1997. Polyps were detected in 709 patients. Five hundred twenty-three patients who had a polyp at sigmoidoscopy and full colonoscopy completed within one year were included in this study. 120 patients (23%) had a proximal polyp detected at colonoscopy. The prevalence of proximal polyps and histologically advanced polyps was related to the size, number, and histology of the distal index polyp found at sigmoidoscopy. However, the absolute difference in prevalence of proximal polyps stratified by dings at sigmoidoscopy was small. A total of 5 adenocarcinomas were detected in the proximal colon. All proximal cancers detected at colonoscopy occurred in patients with a distal polyp less than 10 mm. Our data emphasize the importance of colonoscopy in all patients with a polyp detected at sigmoidoscopy independent of its size and histology.     

Difference in the prevalence of advanced colon adenoma between patients with gastric neoplasm and healthy people: A STROBE-compliant study

We compared the prevalence of adenoma and cancerous colon polyps in patients undergoing endoscopic removal or gastric surgery for gastric adenoma or gastric cancer and in healthy individuals.The medical records of 707 patients with gastric neoplasm and 798 age- and sex-matched healthy subjects were retrospectively analyzed between January 2010 and July 2018. The clinicopathological characteristics, prevalence of colorectal neoplasm diagnosed by colonoscopy, and risk factors for colorectal polyps were also investigated.When comparing the two groups, the prevalence of overall colorectal polyps and its distribution was not different between the two groups (54.0% vs.49.5%, P = .079), whereas, the number of colon polyps (1.20 ± 1.71 vs 0.99 ± 1.54, P = .015) and the maximal size (3.53 ± 6.14 vs 2.08 ± 2.88, P < .001) were significantly larger in the gastric neoplasm group. The prevalence of advanced colon adenoma was significantly higher in the gastric neoplasm group (10.7% vs 3.8%, P < .001). Risk factors such as elevated glucose levels and the presence of gastric neoplasm were related to the prevalence of all colon polyps. The presence of gastric neoplasm is an important risk factor for advanced colon polyps.Patients with gastric neoplasms had a significantly higher prevalence of advanced colon adenoma. Advanced colon adenoma is associated with the chain from benign adenomas through malignant altered adenomas to advanced colon cancer. Thus, patients with gastric neoplasm are regarded as a high-risk group for colorectal cancer and are recommended for screening colonoscopy at the time of diagnosis.     

Colorectal neoplasia in Asia: a multicenter colonoscopy survey in symptomatic patients

BACKGROUND: The incidence of colorectal cancer is rising rapidly in some Asian countries. OBJECTIVE: To determine the prevalence and the distribution of colorectal neoplasm in Asian populations. DESIGN: A multicenter colonoscopy survey. PATIENTS: Between July 2004 and April 2005, consecutive symptomatic patients undergoing colonoscopic examinations in 10 different Asian countries. SETTING: The location and the histologic features of all colonic neoplasms were recorded. Advanced neoplasm was defined as adenoma larger than 10 mm in size, with >25% villous features or with high-grade dysplasia or invasive carcinoma. MAIN OUTCOME MEASUREMENTS: The prevalence and the distribution of colorectal neoplasm and advanced neoplasm. RESULTS: A total of 5464 eligible patients underwent colonoscopy. Advanced neoplasm was found in 512 patients (9.4%). Factors associated with the presence of advanced neoplasm in this symptomatic Asian population included male sex (relative risk [RR] 1.52, 95% confidence interval [CI] 1.26-1.84), older age (RR 1.05, 95% CI 1.04-1.06), and ethnicity (P = .001). Advanced proximal neoplasm was detected in 136 patients (2.5%); 83 (61.0%) of the patients had normal distal colon. The RR of proximal advanced neoplasm was 2.5, 95% CI 1.7-3.7 in those with any adenoma in the distal colon compared with those with normal distal colon. LIMITATIONS: Possible underrepresentation of some ethnic groups because of uneven ethnic group distribution and the lack of population-based registry. CONCLUSIONS: This was the first multicenter colonoscopy survey that examined the characteristics of colorectal neoplasm in Asia. The results will have important implications on the planning for future colorectal cancer screening in this region.     

Colonic neoplasia in patients with nonspecific GI symptoms

BACKGROUND: The purpose of this study was to determine the prevalence rate of colonic polyps or masses 1 cm or greater in diameter in patients with nonspecific abdominal symptoms, from diverse practice settings, using a national endoscopic database. METHODS: Consecutive patients undergoing colonoscopy were included based on procedure indication. Endoscopic data were generated with a computer database at each practice site, transmitted to a central data bank and merged with data from multiple sites for analysis. Group 1 patients had nonspecific abdominal symptoms, which were defined as pain, constipation and diarrhea. Group 2 patients had a positive fecal occult blood test. Group 3 patients were asymptomatic, undergoing screening colonoscopy. Serious colon pathology was defined as a polyp or mass greater than 9 mm in size. RESULTS: Data were collected from 31 practice sites in 21 states during a period of 18 months. Of the 20,745 colonoscopy examinations, 9.2% were performed to evaluate patients with nonspecific abdominal symptoms, excluding other indications. Among patients with nonspecific symptoms 7.27% had polyp(s) 1 cm or greater in diameter compared with 17.05% of patients with positive fecal occult blood test (odds ratio 2.12: CI [1.73, 2.60]; p < 0.001). Patients with nonspecific symptoms had similar rates of large polyps as asymptomatic patients (7.27% vs. 6.45%, p = 0.32). Multivariate analysis identified several independent variables including increasing age, male gender and practice site at a Veterans Affairs Medical Center. CONCLUSIONS: In diverse, practice-based settings, patients with nonspecific abdominal symptoms who are referred for colonoscopy do not have a higher risk of serious colonic pathology than asymptomatic patients.     

Colonoscopic evaluation of hematochezia in low and average risk patients for colorectal cancer： A prospective study

INTRODUCTION Hematochezia def ined as a chronic intermittent passage of a small amount of bright red blood from the rectum is a clinical problem frequently found in adults of all ages. Its prevalence in the apparently healthy general population is between…     

Pros and cons of colonoscopy in management of acute lower gastrointestinal bleeding

Acute lower gastrointestinal bleeding (LGIB) is a frequent gastrointestinal cause of hospitalization, particularly in the elderly, and its incidence appears to be on the rise. Endoscopic and radiographic measures are available for the evaluation and treatment of LGIB including flexible sigmoidoscopy, colonoscopy, angiography, radionuclide scintigraphy and multi-detector row computed tomography. Although no modality has emerged as the gold standard in the management of LGIB, colonoscopy is the current preferred initial test for the majority of the patients presenting with hematochezia felt to be from a colon source. Colonoscopy has the ability to diagnose all sources of bleeding from the colon and, unlike the radiologic modalities, does not require active bleeding at the time of the examination. In addition, therapeutic interventions such as cautery and endoclips can be applied to achieve hemostasis and prevent recurrent bleeding. Studies suggest that colonoscopy, particularly when performed early in the hospitalization, can decrease hospital length of stay, rebleeding and the need for surgery. However, results from available small trials are conflicting and larger, multicenter studies are needed. Compared to other management options, colonoscopy is a safe procedure with complications reported in less than 2% of patients, including those undergoing urgent examinations. The requirement of bowel preparation (typically 4 or more liters of polyethylene glycol), the logistical complexity of coordinating after-hours colonoscopy, and the low prevalence of stigmata of hemorrhage complicate the use of colonoscopy for LGIB, particularly in urgent situations. This review discusses the above advantages and disadvantages of colonoscopy in the management of acute lower gastrointestinal bleeding in further detail.     

Colonic Neoplasms in Asymptomatic First-Degree Relatives of Colon Cancer Patients

First-degree relatives of colon cancer patients are at elevated risk for developing colorectal neoplasms. In order to assess the potential usefulness of screening by colonoscopy in this high-risk population, we reviewed the records of 48 colonoscopies performed on asymptomatic patients who were self- or physician-referred for colonoscopy because of a history of one or more first-degree relatives with colon cancer. Twelve (25%) had at least one adenomatous polyp, but no significant atypia was detected. No cancers were detected. One third of the lesions were beyond the reach of a flexible sigmoidoscope. This apparent increase in the prevalence of adenomas was most striking (46%) among men over the age of 50. These preliminary results demonstrate that colonoscopy is effective in detecting and removing adenomatous polyps in a substantial fraction of asymptomatic patients whose sole risk-factor is being a first-degree relative of a patient with colon cancer. Further studies in larger populations are warranted to determine the use of colonoscopy in screening these high-risk individuals.     

Limited water infusion decreases pain during minimally sedated colonoscopy

AIM:To investigate a limited water infusion method in colonoscopy.METHODS:Consecutive patients undergoing minimally sedated colonoscopy were randomized to receive air insufflation(n = 89) or water infusion limited to the rectum,sigmoid colon and descending colon(n = 90).Completion rates,cecal intubation times,procedure times,need for abdominal compression,turning of patients and levels of discomfort were evaluated.RESULTS:Completion rates,total procedure times,need for abdominal compression,and turning of p...     

不同时间点服用西甲硅油在结肠镜检查前肠道准备中的作用

【】目的 探讨不同时间点服用西甲硅油在结肠镜检查前肠道准备中的作用。方法 将270例拟行结肠镜检查的患者随机分为3组,所有患者均在结肠镜检查前4小时服用聚乙二醇电解质清洁肠道。A组：结肠镜检查前2小时口服西甲硅油30ml;B组：结肠镜检查前1小时服用西甲硅油30ml。C组：结肠镜检查前0.5小时服用西甲硅油30ml。观察3组患者的肠道清洁程度、肠腔内气泡情况、息肉检出率及操作时间。结果 三组患者之间的肠道清洁程度差异无统计学意义(P>0.05)。与A组和C组相比,B组的肠腔内气泡明显减少(P<0.05),息肉检出率明显升高(P<0.05),操作时间明显降低(P<0.05)。A组和C组相比,肠腔内气泡情况、息肉检出率及操作时间无明显差异(P>0.05)。结论 结肠镜检查前1小时口服西甲硅油30ml可减少肠腔内气泡、提高息肉检出率,并缩短操作时间。     

Sporadic colonic hamartomas in adults: a retrospective study

BACKGROUND: Colonic hamartomas are uncommon in adults. The aims of this study were to determine (1) the prevalence of colonic hamartomas in an adult population undergoing colonoscopy and (2) the clinical, endoscopic, and histologic features of colonic hamartomas in adult patients. METHODS: A pathology database identified 19 adult patients of 12,707 patients with colonic hamartomas in the 11-year study period from January 1992 to October 2002. An endoscopic computer database provided information about the number of colonoscopies performed and the presence or the absence of colonic polyp(s) in study patients. Charts of patients with colonic hamartomas were reviewed, and clinical and demographic data were collated. RESULTS: Nineteen patients were found to have colonic hamartomas. The mean age of these patients was 55 years, with an age distribution ranging from 25 to 81 years. The prevalence of colonic hamartomas in this study population was 0.15%. The prevalence of hamartomas in patients with colon polyps at index colonoscopy was 0.073%. Colonic hamartomas were more common in men than in women. The indication for colonoscopy for the majority (68%) of patients was hematochezia or the presence of occult blood in the stool. Three fourths of the polyps were greater than 1 cm in diameter, and 89% were pedunculated. Two thirds of the hamartomatous polyps were localized to the rectosigmoid region. Endoscopic characteristics of hamartomas were indistinguishable from adenomas. CONCLUSIONS: Colonic hamartomas in adults are rare. They tend to be single, pedunculated, and localized predominantly in the rectosigmoid region. Endoscopic resection of colonic hamartomas was successful in all patients.     

Diverticular disease as a risk factor for sigmoid colon adenomas

BACKGROUND: Diverticular disease and colorectal neoplasia share similar epidemiological features and risk factors. AIM: To evaluate a possible association between diverticular disease and both adenomas and colorectal cancer in patients undergoing total colonoscopy. METHODS: Overall, 630 consecutive patients were recruited from the 3 Units. Inclusion criteria were age over 45 years and the performance of total colonoscopy. Demographic and clinical data were recorded. Adenomas were defined as advanced when their size was >1 cm in diameter, and/or the percentage of the villous component was >30% and/or high grade dysplasia was present. RESULTS: At endoscopy, 291 (47%) out of 630 patients presented evidence of diverticular disease. Adenomas were found in 92 (31.9%) patients with diverticular disease and in 98 (28.9%) patients without [p=ns]. The prevalence of adenomas located in the sigmoid colon was significantly higher in patients with diverticula than in controls (64.1% vs 41.8%; p<0.05). Similarly, the detection of advanced adenomas located in the sigmoid colon was more likely in patients with diverticula than in controls (59.6% vs 37.5%; p<0.05). Colorectal cancer prevalence was similar in patients with and without diverticula (8.3% vs 7.1%; p=ns), and no difference was detected regarding site, between the two groups. CONCLUSIONS: Patients with diverticular disease have a higher risk of harbouring adenomas and advanced adenomas in the sigmoid colon. This observation should be taken into account in screening and surveillance programmes for colorectal neoplasia.     

Prospective evaluation of screening colonoscopy: who is being screened?

BACKGROUND: Universal access to medical procedures is deemed an advantage of the Canadian health care system. The purposes of this prospective study were to determine the degree to which the practice of colon cancer screening by colonoscopy differed among socioeconomic classes and to assess adherence to screening guidelines. METHODS: Consecutive patients scheduled to undergo colonoscopy at a single center between August 2000 and August 2002 completed a questionnaire that determined patient characteristics and indications for the procedure. The patients were divided into two groups: screening patients, defined as individuals who indicated they were undergoing colonoscopy for screening purposes and were asymptomatic, and a control group, which comprised patients undergoing colonoscopy because of symptoms. Statistical analysis was performed to determine if patients in the screening group had different characteristics with respect to socioeconomic class, compared with the control group. RESULTS: A total of 1088 patients completed the questionnaire: 707 (65%) had colonoscopy because of symptoms, compared with 381 (35%) who underwent a screening examination. Mean age and marital status were similar in both groups. Of all colonoscopy procedures, there was a significantly greater proportion of men undergoing colonoscopy for screening purposes: 199 (52.2%) vs. 294 (41.6%) in the symptomatic group ( p = 0.001). Based on the Cochran-Armitage test, patients in the screening group had significantly higher education levels ( p = 0.004) and household incomes ( p = 0.001). CONCLUSIONS: Income and education level, two indices of socioeconomic status, are statistically significantly higher in patients undergoing screening colonoscopy compared with those having colonoscopy for any other reason.