Prevalence of colorectal neoplasm among patients with newly diagnosed coronary artery disease.

CONTEXT: Colorectal neoplasm and coronary artery disease (CAD) share similar risk factors, and their co-occurrence may be associated. OBJECTIVES: To investigate the prevalence of colorectal neoplasm in patients with CAD in a cross-sectional study and to identify the predisposing factors for the association of the 2 diseases. DESIGN, SETTING, AND PARTICIPANTS: Patients in Hong Kong, China, were recruited for screening colonoscopy after undergoing coronary angiography for suspected CAD during November 2004 to June 2006. Presence of CAD (n = 206) was defined as at least 50% diameter stenosis in any 1 of the major coronary arteries; otherwise, patients were considered CAD-negative (n = 208). An age- and sex-matched control group was recruited from the general population (n = 207). Patients were excluded for use of aspirin or statins, personal history of colonic disease, or colonoscopy in the past 10 years. MAIN OUTCOME MEASURES: The prevalence of colorectal neoplasm in CAD-positive, CAD-negative, and general population participants was determined. Bivariate logistic regression was performed to study the association between colorectal neoplasm and CAD and to identify risk factors for the association of the 2 diseases after adjusting for age and sex. RESULTS: The prevalence of colorectal neoplasm in the CAD-positive, CAD-negative, and general population groups was 34.0%, 18.8%, and 20.8% (P < .001 by chi2 test), prevalence of advanced lesions was 18.4%, 8.7%, and 5.8% (P < .001), and prevalence of cancer was 4.4%, 0.5%, and 1.4% (P = .02), respectively. Fifty percent of the cancers in CAD-positive participants were early stage. After adjusting for age and sex, an association still existed between colorectal neoplasm and presence of CAD (odds ratio [OR], 1.88; 95% confidence interval [CI], 1.25-2.70; P = .002) and between advanced lesions and presence of CAD (OR, 2.51; 95% CI, 1.43-4.35; P = .001). The metabolic syndrome (OR, 5.99; 95% CI, 1.43-27.94; P = .02) and history of smoking (OR, 4.74; 95% CI, 1.38-18.92; P = .02) were independent factors for the association of advanced colonic lesions and CAD. CONCLUSIONS: In this study population undergoing coronary angiography, the prevalence of colorectal neoplasm was greater in patients with CAD. The association between the presence of advanced colonic lesions and CAD was stronger in persons with the metabolic syndrome and a history of smoking.

Intestinal tuberculosis mimicking fistulizing Crohn's disease.

A patient is reported with intestinal tuberculosis that mimicked fistulizing Crohn's disease endoscopically. He had complete resolution of symptoms after a full course of antituberculosis therapy. Gastroenterologists and general physicians should aware of the possibility of intestinal tuberculosis in areas with a high prevalence of tuberculosis infection.

Colonoscopy demand and practice in a regional hospital over 9 years in Hong Kong: resource implication for cancer screening.

BACKGROUND: The incidence of colorectal cancer (CRC) in Hong Kong is rising. The trend of colonoscopy demand is uncertain. AIM: To investigate colonoscopy demand and practice in a Hong Kong regional hospital over the past nine years. METHODS: Colonoscopy data from 1st January 1997 to 31st August 2005 were retrieved and divided into two equal periods for comparison. Colonoscopy practice and findings between the two periods were compared. RESULTS: There was no change in the number of endoscopists and colonoscopy sessions in the two periods. The number of colonoscopy done in the two periods was 2,681 and 2,871, respectively. The indications for screening of CRC/polyp (9.3 vs. 24.7%, p < 0.0001) and surveillance of CRC/polyp (4.7 vs. 10.9%, p < 0.0001) were increased, but decreased for diarrhea (18 vs. 10.2%, p < 0.0001) and per rectal bleeding (19 vs. 8.1%, p < 0.0001). The waiting time was lengthened from 2 to 4 weeks (p < 0.0001). The percentage of colonic adenomas (19.9 vs. 27.2%, p < 0.0001) was increased. A right-shift was observed in both CRC (37 vs. 50%, p = 0.018) and adenoma (21.6 vs. 38.1%, p < 0.0001). CONCLUSION: The number of colonoscopies performed was governed by capacity partly through lengthening of waiting time to cope with demand. Ways to improve capacity for colonoscopies is needed.

Esomeprazole with aspirin versus clopidogrel for prevention of recurrent gastrointestinal ulcer complications.

BACKGROUND AND AIMS: The role of clopidogrel in patients at risk for gastrointestinal complications is uncertain, although it has been recommended for patients who have gastrointestinal intolerance to aspirin. We tested the hypothesis that clopidogrel is as effective as esomeprazole and aspirin in preventing recurrences of ulcer complications. METHODS: This was a prospective, double-blind, randomized, controlled study of 170 patients who developed ulcer bleeding after the use of low-dose aspirin between November 2002 and January 2005. After healing of ulcers and eradication of Helicobacter pylori, if present, patients were assigned randomly to treatment with esomeprazole 20 mg/day and aspirin 100 mg/day (n = 86) or clopidogrel 75 mg/day (n = 84) for 52 weeks. The primary end point was recurrent ulcer complications. RESULTS: During a median follow-up period of 52 weeks, no patient in the esomeprazole group, as compared with 9 patients in the clopidogrel group, developed recurrent ulcer complications. The cumulative incidences of recurrent ulcer complications were 0% in patients receiving esomeprazole and aspirin and 13.6% in patients receiving clopidogrel (absolute difference, 13.6%; 95% confidence interval for the difference, 6.3-20.9; log-rank test, P = .0019). CONCLUSIONS: The combination of esomeprazole and aspirin is superior to clopidogrel in preventing ulcer complications in patients who have a past history of aspirin-related peptic ulcer bleeding.

Incidence and predictors of upper gastrointestinal bleeding in patients receiving low-dose aspirin for secondary prevention of cardiovascular events in patients with coronary artery disease.

AIM: The use of low-dose aspirin to prevent cardiovascular disease events is well established. However, the incidence and predictors of upper gastrointestinal bleeding (UGIB) with its use are unknown. We studied prospectively the incidence and outcome of peptic ulceration in low-dose aspirin users. METHODS: A total of 991 patients with coronary artery disease (CAD) on low-dose aspirin were prospectively followed-up for two years for the occurrence and clinical features of first hospitalized episode of UGIB. RESULTS: UGIB had a bimodal presentation with 45% occurring within four months of aspirin initiation and had an overall prevalence of 1.5% per year. There was no UGIB-related death. Hypertension (OR = 4.6, 95%CI 1.5-14.7, P = 0.009), history of peptic ulceration (OR = 3.1, 95%CI 1.1-9.0, P = 0.039), tertiary education (OR = 3.08, 95%CI 1.1-9.0, P = 0.039) and higher lean body mass (P = 0.016) were independent factors associated with UGIB. Use of nitrate did not reduce UGIB. CONCLUSION: The incidence of UGIB in patients with CAD on long-term low-dose aspirin is low, but is accompanied with significant morbidity. With prolonged use of aspirin, UGIB continues to be a problem for those with risk factors and especially in patients with a history of peptic ulcers, in which UGIB tends to occur early after aspirin therapy.

A patient with long-standing iron-deficient anemia.

BACKGROUND: A 36-year-old Chinese woman presented with cutaneous lupus and was incidentally found to have iron-deficient anemia. She had a history of iron-deficient anemia 13 years previously, for which extensive investigations were carried out; the results of which were all normal. The patient also had pulmonary tuberculosis at that time, for which she received a full course of treatment. She required periodic blood transfusions and iron supplements to maintain her hemoglobin levels. She was subsequently discharged to a family clinic for follow-up until the current presentation. INVESTIGATIONS: Upper endoscopy, colonoscopy, barium meal follow-through, small-bowel enema, (99m)Tc-labeled red-cell scan and double-balloon enteroscopy. DIAGNOSIS: Iron-deficient anemia due to obscure gastrointestinal bleeding caused by two small-bowel hemangiomas. MANAGEMENT: Laparoscopic surgery.

Celecoxib compared with lansoprazole and naproxen to prevent gastrointestinal ulcer complications.

PURPOSE: Selective cyclooxygenase-2 (COX-2) inhibitors cause significantly fewer peptic ulcers than conventional nonselective nonsteroidal anti-inflammatory drugs (NSAIDs) in patients at low risk or high risk for peptic ulcers. On the other hand, proton pump inhibitor co-therapy has also been shown to be effective in preventing relapse of peptic ulcers in high-risk patients using nonselective NSAIDs. We compared the efficacy of a selective COX-2 inhibitor with that of proton pump inhibitor co-therapy in the reduction in the incidence of ulcer relapse in patients with a history of NSAID-related peptic ulcers. MATERIALS AND METHODS: For this study, we recruited 224 patients who developed ulcer complications after NSAID use. We excluded patients who required concomitant aspirin treatment and who had renal impairment. After healing of ulcers and eradication of Helicobacter pylori, patients were randomly assigned to treatment with celecoxib 200 mg daily (n = 120) or naproxen 750 mg daily and lansoprazole 30 mg daily (n = 122) for 24 weeks. The primary endpoint was recurrent ulcer complications. RESULTS: During a median follow-up of 24 weeks, 4 (3.7%, 95% confidence interval [CI] 0.0%-7.3%) patients in the celecoxib group, compared with 7 patients (6.3%, 95% CI 1.6%-11.1%) in the lansoprazole group, developed recurrent ulcer complications (absolute difference -2.6%; 95% CI for the difference -9.1%-3.7%). Celecoxib was statistically non-inferior to lansoprazole co-therapy in the prevention of recurrent ulcer complications. Concomitant illness (hazard ratio 4.72, 95% CI 1.24-18.18) and age 65 years or more (hazard ratio 18.52, 95% CI 2.26-142.86) were independent risk factors for ulcer recurrences. Significantly more patients receiving celecoxib (15.0%, 95% CI 9.7-22.5) developed dyspepsia than patients receiving lansoprazole (5.7%, 95% CI 2.8-11.4. P = .02). CONCLUSIONS: Celecoxib was as effective as lansoprazole co-therapy in the prevention of recurrences of ulcer complications in subjects with a history of NSAID-related complicated peptic ulcers. However, celecoxib, similar to lansoprazole co-therapy, was still associated with a significant proportion of ulcer complication recurrences. In addition, more patients receiving celecoxib developed dyspepsia than patients receiving lansoprazole and naproxen.

Differing coping mechanisms, stress level and anorectal physiology in patients with functional constipation.

AIM: To investigate coping mechanisms, constipation symptoms and anorectal physiology in 80 constipated subjects and 18 controls. METHODS: Constipation was diagnosed by Rome II criteria. Coping ability and anxiety/depression were assessed by validated questionnaires. Transit time and balloon distension test were performed. RESULTS: 34.5% patients were classified as slow transit type of constipation. The total colonic transit time (56 h vs 10 h, P<0.0001) and rectal sensation including urge sensation (79 mL vs 63 mL, P = 0.019) and maximum tolerable volume (110 mL vs 95 mL, P = 0.03) differed in patients and controls. Constipated subjects had significantly higher anxiety and depression scores and lower SF-36 scores in all categories. They also demonstrated higher scores of 'monitoring' coping strategy (14+/-6 vs 9+/-3, P = 0.001), which correlated with the rectal distension sensation (P = 0.005), urge sensation (P=0.002), and maximum tolerable volume (P = 0.035). The less use of blunting strategy predicted slow transit constipation in both univariate (P = 0.01) and multivariate analysis (P = 0.03). CONCLUSION: Defective or ineffective use of coping strategies may be an important etiology in functional constipation and subsequently reflected in abnormal anorectal physiology.

Low-dose rabeprazole, amoxicillin and metronidazole triple therapy for the treatment of Helicobacter pylori infection in Chinese patients.

BACKGROUND: Rabeprazole in combination with amoxicillin and metronidazole (RAM) has been shown to be an effective second-line treatment of Helicobacter pylori infection. The effects were compared of 7-day low-dose and high dose rabeprazole in RAM for the primary treatment of H. pylori infection in Chinese patients. METHODS: Helicobacter pylori-positive dyspeptic patients were randomized to receive either (i) rabeprazole 10 mg, amoxicillin 1000 mg and metronidazole 400 mg (RAM-10) or (ii) high-dose rabeprazole 20 mg, amoxicillin 1000 mg and metronidazole 400 mg (RAM-20), each given twice daily for 7 days. Helicobacter pylori eradication was confirmed by (13)c-urea breath test 5 weeks after stopping medications. side-effects of treatments were documented. RESULTS: A total of 120 patients were eligible for analysis. By intention-to-treat and per-protocol analysis, the eradication rates were 83% and 86% in the RAM-10 group and 75% and 76% in the RAM-20 group, respectively (P = 0.26 and P = 0.17). Both regimens were well-tolerated and compliance was >98% in both groups. CONCLUSIONS: Low-dose rabeprazole in combination with amoxicillin and metronidazole is an effective, economical and well-tolerated therapy for the treatment of H. pylori infection in Chinese population.

Pathophysiology of gastroesophageal reflux diseases in Chinese--role of transient lower esophageal sphincter relaxation and esophageal motor dysfunction.

BACKGROUND AND AIMS: Transient lower esophageal sphincter relaxation (TLESR) is the major mechanism for gastroesophageal reflux in the Western population. The major reflux mechanism in Chinese patients with GERD has not been studied before. METHODS: Fifty-four patients with GERD and 28 controls underwent stationary baseline manometry and the 24-h ambulatory esophageal pH monitoring. TLESRs were measured before and after an 850 kcal meal in the supine position. Primary peristalsis, secondary peristalsis, and esophageal acid clearance were measured by esophageal manometry. RESULTS: Total time esophageal pH

Normal colon transit time in healthy Chinese adults in Hong Kong.

BACKGROUND AND AIM: Colon transit study with radio-opaque markers is helpful in the evaluation of chronic constipation. Normal reference values, based on radio-opaque markers, have not been reported from Chinese adults in Hong Kong. METHODS: Fifty-one healthy Chinese (27 men, age 42 +/- 12 years) were enrolled through a newspaper advertisement. They were requested to fill in detailed dietary records and a gastrointestinal symptom questionnaire. Each subject swallowed, under supervision, a total of three Sitzmarks capsules, one capsule at the same time on each of day 1, 2 and 3. Abdominal films were taken on days 4 and 7, also at the same time of the day. Total and segmental transit times were calculated using Metcalf's method. RESULTS: The upper limit of normal total colonic transit time (CTT) was 62 h, while right, left and rectosigmoid CTT were 16 h, 31 h and 32 h, respectively. Women of age 18-35 years had a longer rectosigmoid and total CTT compared with their male counterparts (mean total CTT: 39 h vs 18 h, P = 0.05). The CTT appeared to be unaffected by the usual dietary components. CONCLUSION: A single normal reference value for CTT appeared to be applicable to Chinese adults in Hong Kong, irrespective of age, sex and dietary content. However, young Chinese women (age 18-35 years) appeared to have longer total and rectosigmoid CTT.

Outpatients undergoing therapeutic endoscopic retrograde cholangiopancreatography: six-hour versus overnight observation.

BACKGROUND AND AIM: The purpose of the present retrospective study was to compare the proportion of post-endoscopic retrograde cholangiopancreatography (ERCP) complications detected with 6-h observation followed by same-day discharge (SDD) versus overnight observation (OO) after therapeutic ERCP. METHODS: There were 134 outpatients in the SDD group and 178 outpatients in the OO group. The SDD group was discharged after a 6-h observation while the OO group was discharged after overnight observation. Patients in the SDD group were admitted from the recovery room for evaluation if they had systolic blood pressure (BP) < 100 mmHg, pulse > 100/min, temperature > 37.5 degrees C, or post-procedure abdominal pain. The primary outcome of the present study was the proportion of post-ERCP complications detected within the observational period between the SDD group and the OO group. RESULTS: The post-ERCP complication rate of therapeutic ERCP in the SDD and OO groups were 9.7% and 9.6%, respectively (P = 0.964). Eleven patients (8.2%) in the SDD group and 13 patients (7.3%) in the OO group were found to have post-ERCP complications within the observation period. There was no significant difference in the proportion of post-ERCP complications detected within the observational period between the two groups (P = 0.672). CONCLUSION: Outpatient therapeutic ERCP with observation of 6 h can detect the same proportion of patients with post-ERCP complications as overnight observation.

Population based study of noncardiac chest pain in southern Chinese: prevalence, psychosocial factors and health care utilization.

AIM: Population-based assessment of noncardiac chest pain (NCCP) is lacking. The aim of this study was to evaluate the prevalence, psychosocial factors and health seeking behaviour of NCCP in southern Chinese. METHODS: A total of 2 209 ethnic Hong Kong Chinese households were recruited to participate in a telephone survey to study the epidemiology of NCCP using the Rose angina questionnaire, a validated gastroesophageal reflux disease (GERD) questionnaire and the hospital anxiety-depression scale. NCCP was defined as non-exertional chest pain according to the Rose angina questionnaire and had not been diagnosed as ischaemic heart diseases by a physician. RESULTS: Chest pain over the past year was present in 454 subjects (20.6%, 95% CI 19-22), while NCCP was present in 307 subjects (13.9%, 95% CI 13-15). GERD was present in 51% of subjects with NCCP and 34% had consulted a physician for chest pain. Subjects with NCCP had a significantly higher anxiety (P<0.001) and depression score (P=0.007), and required more days off (P=0.021) than subjects with no chest pain. By multiple logistic regression analysis, female gender (OR 1.9, 95% CI 1.1-3.2), presence of GERD (OR 2.8, 95% CI 1.6-4.8), and social life being affected by NCCP (OR 6.9, 95% CI 3.3-15.9) were independent factors associated with health seeking behaviour in southern Chinese with NCCP. CONCLUSION: NCCP is a common problem in southern Chinese and associated with anxiety and depression. Female gender, GERD and social life affected by chest pain were associated with health care utilization in subjects with NCCP.

Helicobacter pylori eradication to prevent gastric cancer in a high-risk region of China: a randomized controlled trial.

CONTEXT: Although chronic Helicobacter pylori infection is associated with gastric cancer, the effect of H pylori treatment on prevention of gastric cancer development in chronic carriers is unknown. OBJECTIVE: To determine whether treatment of H pylori infection reduces the incidence of gastric cancer. DESIGN, SETTING, AND PARTICIPANTS: Prospective, randomized, placebo-controlled, population-based primary prevention study of 1630 healthy carriers of H pylori infection from Fujian Province, China, recruited in July 1994 and followed up until January 2002. A total of 988 participants did not have precancerous lesions (gastric atrophy, intestinal metaplasia, or gastric dysplasia) on study entry. INTERVENTION: Patients were randomly assigned to receive H pylori eradication treatment: a 2-week course of omeprazole, 20 mg, a combination product of amoxicillin and clavulanate potassium, 750 mg, and metronidazole, 400 mg, all twice daily (n = 817); or placebo (n = 813). MAIN OUTCOME MEASURES: The primary outcome measure was incidence of gastric cancer during follow-up, compared between H pylori eradication and placebo groups. The secondary outcome measure was incidence of gastric cancer in patients with or without precancerous lesions, compared between the 2 groups. RESULTS: Among the 18 new cases of gastric cancers that developed, no overall reduction was observed in participants who received H pylori eradication treatment (n = 7) compared with those who did not (n = 11) (P =.33). In a subgroup of patients with no precancerous lesions on presentation, no patient developed gastric cancer during a follow-up of 7.5 years after H pylori eradication treatment compared with those who received placebo (0 vs 6; P =.02). Smoking (hazard ratio [HR], 6.2; 95% confidence interval [CI], 2.3-16.5; P<.001) and older age (HR, 1.10; 95% CI, 1.05-1.15; P<.001) were independent risk factors for the development of gastric cancer in this cohort. CONCLUSIONS: We found that the incidence of gastric cancer development at the population level was similar between participants receiving H pylori eradication treatment and those receiving placebo during a period of 7.5 years in a high-risk region of China. In the subgroup of H pylori carriers without precancerous lesions, eradication of H pylori significantly decreased the development of gastric cancer. Further studies to investigate the role of H pylori eradication in participants with precancerous lesions are warranted.

Does the addition of endoscopic sphincterotomy to stent insertion improve drainage of the bile duct in acute suppurative cholangitis?

BACKGROUND: The treatment of patients with bile duct stones and acute suppurative cholangitis is emergent biliary decompression either by endoscopic sphincterotomy, nasobiliary drainage, or stent insertion. The aim of this retrospective study was to determine whether endoscopic sphincterotomy, in addition to an internal endoprosthesis, improves outcome for patients with acute suppurative cholangitis. METHODS: A total of 74 patients with acute suppurative cholangitis and bile duct stones were included in the study; 37 had endoscopic sphincterotomy before insertion of plastic stent (Group 1), and 37 had a plastic stent inserted through an intact papilla (Group 2). RESULTS: The success rates for stent insertion in Groups 1 and 2 were, respectively, 89.2% and 86.5% (p = 1.000). The complication rates in Group 1 and Group 2 were, respectively, 10.8% and 2.7% (p = 0.358). The median (interquartile range 25th-75th percentile) durations of hospital stay for patients in Group 1 and Group 2 were, respectively, 6.5 (4-11) days and 7 (5-12) days (p = 0.614). The median (interquartile range) lengths of time for resolution of jaundice in Group 1 and Group 2 were, respectively, 3 (2-6) days versus 4 (2-5) days (p = 0.981). CONCLUSIONS: Endoscopic sphincterotomy, in addition to biliary stent insertion, is not required for successful biliary decompression in patients with severe acute cholangitis.

Effects of primary metronidazole and clarithromycin resistance to Helicobacter pylori on omeprazole, metronidazole, and clarithromycin triple-therapy regimen in a region with high rates of metronidazole resistance.

The aim of this study was to investigate the effect of metronidazole resistance (MtzR) and clarithromycin resistance (ClaR) on the eradication rate for omeprazole, clarithromycin, and metronidazole triple-therapy regimen and on the development of posttherapy drug resistance in a region of high rates of MtzR. One hundred ninety-six Helicobacter pylori isolates were recovered from patients with duodenal ulcer, gastric ulcer, or nonulcer dyspepsia during upper endoscopy. The prevalences of MtzR, ClaR, and dual resistance were 37.8%, 13.8%, and 8.7%, respectively. The intention-to-treat eradication rates for metronidazole-susceptible (87.2% vs. 67.6%; P=.001) and clarithromycin-susceptible (86.4% vs. 40.7%; P<.001) strains were significantly higher than the rates for resistant strains. Multiple logistic regression analysis implicated younger age (<40 years old), MtzR, ClaR, and the diagnosis of nonulcer dyspepsia as independent factors that predicted treatment failure. The rates of posttreatment MtzR, ClaR, and dual resistance were 88%, 88%, and 75%, respectively. MtxR and ClaR significantly affected the success of eradication therapy. Posttreatment rates of resistance were high and were related to the presence of pretreatment antibiotic resistance.

Antralization at the edge of proximal gastric ulcers: does Helicobacter pylori infection play a role?

AIM: To determine the prevalence of antralization at the edge of proximal gastric ulcers, and the effect of H. pylori eradication on the mucosal appearances. METHODS: Biopsies were taken from the antrum, body and the ulcer edge of patients with benign proximal gastric ulcers before and one year after treatment. Gastric mucosa was classified as antral, transitional or body type. H. pylori positive patients received either triple therapy, or omeprazole. RESULTS: Patients with index ulcers in the incisura, body or fundus (n=116) were analyzed. Antral-type mucosa was more prevalent at the ulcer edge in H. pylori-positive patients than H. pylori-negative patients (93 % vs 60 %, OR=8.95, 95 %CI: 2.47-32.4, P=0.001). At one year, there was a significant reduction in the prevalence of antralization (from 93 % to 61 %, P=0.004) at the ulcer edge in patients with H. pylori being eradicated. However, there was no difference in the prevalence of antralization at the ulcer edge in those with persistent infection. CONCLUSION: H. pylori infection is associated with antralization at the edge of proximal gastric ulcers, which may be reversible in some patients after eradication of the infection.

Evaluation of an automated immunochemical fecal occult blood test for colorectal neoplasia detection in a Chinese population.

BACKGROUND: Most commercial fecal occult blood tests (FOBT) used for colorectal carcinoma screening of Western populations are guaiac-based, manually developed, subjective, and sensitive to dietary components. Preliminary studies demonstrated the unsuitability of these tests for screening a Chinese population. The goal of the current study was to evaluate the performance characteristics of a human hemoglobin-specific automated immunochemical FOBT, the Magstream 1000/Hem SP (Fujirebio, Inc., Tokyo, Japan), in a Chinese population referred for colonoscopy. METHODS: Two hundred fifty consecutive patients who were referred for colonoscopy and met the study inclusion criteria provided samples for the immunochemical FOBT (without dietary restrictions) from two successive stool specimens. Tests were developed with an automated instrument that had an adjustable sensitivity threshold. The sensitivity, specificity, and positive predictive value for detecting colorectal adenomas and carcinomas were calculated according to the manufacturer's instructions over a range of sensitivity levels. RESULTS: At the optimal threshold level, the sensitivity, specificity, and positive predictive value for detection of significant colorectal neoplasia (adenomas >or= 1.0 cm and carcinomas) were 62%, 93%, and 44%, respectively. The test was easy to use, and results did not depend on operator experience. CONCLUSIONS: The automated immunochemical FOBT used in the current study was a robust, convenient, and useful tool for colorectal carcinoma screening in the study population.