Carbon dioxide-insufflated colonoscopy: an ignored superior technique

Colonoscopy and barium enema are complementary studies in the diagnosis of the cause of lower intestinal bleeding. The air usually insufflated during colonoscopy often makes it impossible to perform a good barium enema on the same day. As a possible solution to this problem, we studied the quality of barium enemas performed immediately following carbon dioxide-insufflated colonoscopy. All 15 patients who underwent unsuccessful total colonoscopies using carbon dioxide insufflation were able to have barium enemas performed the same day in contrast to only one out of 15 patients who had air-insufflated colonoscopy. In a survey of all hospitals in Illinois with 150 beds or more, we found only 15 of 146 hospitals used carbon dioxide for colonoscopy insufflation. We recommend the routine use of carbon dioxide for colonoscopic insufflation not only for greater safety and comfort for the patient, but also for the convenience and cost savings.     

The Introduction and Development of Colonoscopy within a Defined Population in Sweden

Background: Our aim was to describe, in a population-based setting, the use of colonoscopy over time with special emphasis on indications, the competence of the endoscopists, and the frequency of total colonoscopies and to compare the number of colonoscopies with that of barium enemas. Methods: All colonoscopy records during 1979-95 in a Swedish county (population, 258 000) were retrieved. Information was collected about the patients' demographics, the endoscopists, indications, findings, and type of colonoscopy. Results: A total of 6066 colonoscopies were performed in 4304 patients by 62 endoscopists. Of these, 562 were not intended to be complete; of the other 5504 colonoscopies, 4153 were complete (75%). Of the patients 77% had undergone colonoscopy once, 14% twice, and 9% three times or more. Among the endoscopists 73% never performed more than 50 colonoscopies, and 5% did more than 700 colonoscopies. Bleeding as an indication increased from 10% to 31%; polyps decreased from 30% to 10%, and unclear X-ray findings decreased from 28% to 4%. Diarrhoea and abdominal pain, both 0% in 1979, increased to 6% and 5%, respectively. Surveillance (cancer, polyps, colitis) was fairly stable, at 25%. Both the rate of complete colonoscopies and the proportion of colonoscopies done by experienced endoscopists increased with time. The annual number of barium enemas was relatively constant until 1992 but then decreased. Conclusions: The increased use of colonoscopy has resulted in a decrease in barium enemas. The competence of the endoscopists increased, resulting in a higher rate of complete colonoscopies.     

The introduction and development of colonoscopy within a defined population in Sweden

BACKGROUND: Our aim was to describe, in a population-based setting, the use of colonoscopy over time with special emphasis on indications, the competence of the endoscopists, and the frequency of total colonoscopies and to compare the number of colonoscopies with that of barium enemas. METHODS: All colonoscopy records during 1979-95 in a Swedish county (population, 258,000) were retrieved. Information was collected about the patients' demographics, the endoscopists, indications, findings, and type of colonoscopy. RESULTS: A total of 6066 colonoscopies were performed in 4304 patients by 62 endoscopists. Of these, 562 were not intended to be complete; of the other 5504 colonoscopies, 4153 were complete (75%). Of the patients 77% had undergone colonoscopy once, 14% twice, and 9% three times or more. Among the endoscopists 73% never performed more than 50 colonoscopies, and 5% did more than 700 colonoscopies. Bleeding as an indication increased from 10% to 31%; polyps decreased from 30% to 10%, and unclear X-ray findings decreased from 28% to 4%. Diarrhoea and abdominal pain, both 0% in 1979, increased to 6% and 5%, respectively. Surveillance (cancer, polyps, colitis) was fairly stable, at 25%. Both the rate of complete colonoscopies and the proportion of colonoscopies done by experienced endoscopists increased with time. The annual number of barium enemas was relatively constant until 1992 but then decreased. CONCLUSIONS: The increased use of colonoscopy has resulted in a decrease in barium enemas. The competence of the endoscopists increased, resulting in a higher rate of complete colonoscopies.     

Iatrogenic perforation of the colon and rectum

In eight years at Cook County Hospital, 42,000 barium enemas, 16,325 proctosigmoidoscopies, and 1207 colonoscopies were performed. All endoscopic procedures were done by the house staff. There were three perforations due to proctosigmoidoscopy, with one death; three perforations due to colonoscopy, with no deaths; and seven perforations due to barium enema, with no survivors. The adjuvant effect of barium sulfate is proposed as the most likely cause for this excessively high mortality in barium-enema perforation. Read at the meeting of the American Society of Colon and Rectal Surgeons, Colorado Springs, Colorado, June 7 to 11, 1981.     

Abdominal ultrasound after colonoscopy with insufflation of carbon dioxide versus air

Objective. To investigate whether the use of carbon dioxide (CO₂) compared with air insufflation during colonoscopy improves ultrasonography after the procedure. Material and methods. In a double-blind trial, 30 patients were randomized to insufflation with CO₂ or air. Thirty minutes after colonoscopy abdominal ultrasound was performed. Immediately after ultrasonography, the ultrasound quality of the liver, gallbladder, biliary ducts, pancreas, spleen, kidneys, abdominal vessels, antrum, bowel, urinary bladder and prostate/uterus was evaluated for optimal ultrasound scanning quality, minor reduction of scanning conditions, major reduction of scanning conditions and unacceptable scanning conditions. Results. Ultrasound quality 30 min after colonoscopy was significantly better when using CO₂ insufflation instead of air (p<0.003). Significant improvement in imaging quality was observed for the liver, portal vein, splenic vein, all three divisions of the pancreas, aorta, coeliac trunk, superior mesenteric artery, iliac vessels, left kidney and uterus. Conclusions.Ultrasound investigation can be done after a colonoscopy with CO₂ insufflation, whereas it is not recommended after a colonoscopy with air insufflation. In selected cases, this approach may enable and improve post-colonoscopy ultrasound scanning.     

Afternoon colonoscopies have higher failure rates than morning colonoscopies

BACKGROUND: There are several known predictors of an incomplete colonoscopy or difficult colonoscopy. In addition, inadequate bowel preparation has been reported in procedures scheduled later in the day. Operator fatigue, which tends to be higher as the day passes on, may also impact colonoscopy completion rate. AIMS: To determine the influence of performing outpatient colonoscopies in the afternoon versus morning on the completion rates of colonoscopy and adequacy of bowel preparation. METHODS: Retrospective chart review of all outpatient colonoscopies performed between November 2003 and October 2004 in the Division of Gastroenterology at MetroHealth Medical Center in Cleveland, Ohio. Patient demographics, indications for procedure, and colonoscopic findings were reviewed. Patients received polyethylene glycol electrolyte-based bowel preparation in the evening prior to the day of the scheduled colonoscopy. RESULTS: A total of 2,087 colonoscopies was performed, of which 1,084 were in the morning and 999 were in the afternoon. Patients in the morning and afternoon were similar in regards to the known risk factors predictive of an incomplete colonoscopy. The incompletion rate was significantly higher in the afternoon compared to the morning (6.5% vs 4.1%, P= 0.013, OR for incompletion was 1.64, CI 1.11-2.44). Inadequate bowel preparation was found in 167 out of 1,084 (15.4%) colonoscopies in the morning and 197 out of 999 (19.7%) colonoscopies in the afternoon (P= 0.011). Even after excluding incomplete colonoscopies due to poor bowel preparation precluding examination, the incompletion rate was still higher in the afternoon (5% vs 3.2%, P= 0.043, OR 1.60, CI 1.03-2.51). CONCLUSIONS: Scheduling of colonoscopies in the afternoon compared to the morning may be an independent predictor of an incomplete colonoscopy and inadequate bowel preparation. According to our study findings, scheduling of all outpatient colonoscopies preferentially in the morning would avoid suboptimal procedures in 5% of patients and the need for unnecessary repeat colonoscopy or an alternative imaging study in 2.4% of patients.     

CO2 insuffiation for potentially difficult colonoscopies： Efficacy when used by less experienced colonoscopists

AIM: To clarify the effectiveness of CO_2 insufflation in potentially difficult colonoscopy cases, particularly in relation to the experience level of colonoscopists. METHODS: One hundred twenty potentially difficult cases were included in this study, which involved females with a low body mass index and patients with earlier abdominal and/or pelvic open surgery or previously diagnosed left-side colon diverticulosis. Patients receiving colonoscopy examinations without sedation using a pediatric variable-stiffness colonoscope were divided into two groups based on either CO_2 or standard air insufflation. Both insufflation procedures were also evaluated according to the experience level of the respective colonoscopists who were divided into an experienced colonoscopist (EC) group and a less experienced colonoscopist (LEC) group. Study measurements included a 100-mm visual analogue scale (VAS) for patient pain during and after colonoscopy examinations, in addition to insertion to the cecum and withdrawal times. RESULTS: Examination times did not differ, however, VAS scores in the CO_2 group were significantly better than in the air group (P < 0.001, two-way ANOVA) from immediately after the procedure and up to 2 h later. There were no significant differences between either insufflation method in the EC group (P = 0.29), however, VAS scores for CO_2 insufflation were significantly better than air insufflation in the LEC group (P = 0.023) immediately after colonoscopies and up to 4 h afterwards. CONCLUSION: CO_2 insufflation reduced patient pain after colonoscopy in potentially difficult cases when performed by LECs.     

CO2 insufflation for potentially difficult colonoscopies:Efficacy when used by less experienced colonoscopists

AIM: To clarify the effectiveness of CO_2 insufflation in potentially difficult colonoscopy cases, particularly in relation to the experience level of colonoscopists. METHODS: One hundred twenty potentially difficult cases were included in this study, which involved females with a low body mass index and patients with earlier abdominal and/or pelvic open surgery or previously diagnosed left-side colon diverticulosis. Patients receiving colonoscopy examinations without sedation using a pediatric variable-stiffness colonoscope were divided into two groups based on either CO_2 or standard air insufflation. Both insufflation procedures were also evaluated according to the experience level of the respective colonoscopists who were divided into an experienced colonoscopist (EC) group and a less experienced colonoscopist (LEC) group. Study measurements included a 100-mm visual analogue scale (VAS) for patient pain during and after colonoscopy examinations, in addition to insertion to the cecum and withdrawal times. RESULTS: Examination times did not differ, however, VAS scores in the CO_2 group were significantly better than in the air group (P < 0.001, two-way ANOVA) from immediately after the procedure and up to 2 h later. There were no significant differences between either insufflation method in the EC group (P = 0.29), however, VAS scores for CO_2 insufflation were significantly better than air insufflation in the LEC group (P = 0.023) immediately after colonoscopies and up to 4 h afterwards. CONCLUSION: CO_2 insufflation reduced patient pain after colonoscopy in potentially difficult cases when performed by LECs.     

The role of colonoscopy in the assessment of patients with colorectal cancer

A retrospective review of 176 patients with adenocarcinoma of the colon who underwent total colonoscopy preoperatively demonstrated synchronous carcinomas in 3.4 percent and synchronous polyps in 55.1 percent. Full-column barium enemas (68 patients) failed to identify cancer in 22 percent of patients and synchronous polyps in 58 percent of patients, a statistically significant (P<0.001) number of falsenegative examinations. Double-contrast barium enemas (30 patients) failed to identify cancer in 27 percent of patients and synchronous polyps in 42 percent of patients, also a statistically significant (P<0.007) number of false-negative examinations. Full column and air contrast barium enemas identified all index cancers with distant metastases. Air-contrast barium enemas failed to identify 40 percent of “early” index cancers (confined to the bowel wall, negative nodes), and full-column barium enemas failed to identify 32 percent. The incidence of synchronous carcinoma and polyps underscores the need for total colon evaluation when a primary carcinoma is detected. Because of the poor accuracy of barium studies, total colonoscopy is the method of choice for this evaluation. Read at the meeting of the American Society of Colon and Rectal Surgeons, San Diego, California, May 5 to 10, 1985.     

Limitations of Barium Enema Performed as an Adjunct to Incomplete Colonoscopy

PURPOSE Colonoscopy is believed to be inadequate in 4 to 24 percent of procedures. Barium enema often is utilized to complete the examination. In radiology literature, a successful barium enema in this setting requires only that the cecum has been reached. In this study, completion barium enema was assessed for both completeness and quality of proximal visualization. METHODS The charts of 16,216 patients undergoing colonoscopy at Saint Vincent Health Center from July 1995 to July 2003 were reviewed to identify patients who underwent barium enema within six months of an incomplete colonoscopy. Incomplete colonoscopies were audited for history of previous abdominal/pelvic surgery, level of colon attained, and apparent reasons for failure. Corresponding barium enema reports were evaluated in a similar fashion. RESULTS In 485 patients (2.9 percent), colonoscopy was incomplete. One hundred eighteen patients underwent barium enema after incomplete colonoscopy. In these patients, sharp angulation (42 percent) or redundancy/looping (31 percent) most often limited endoscopy. Among the barium enema studies, 91 (77 percent) were technically adequate. Twenty-seven studies were suboptimal (poor preparation/intolerance = 7, redundancy = 6, poor filling = 6, stricture/narrowing = 6, severe diverticulosis = 2). Two patients demonstrated additional polyps. There was no correlation between reasons for endoscopic failure and inadequacy of barium enema. Completeness of barium enema was not affected by previous pelvic surgery. Immediate barium enema was no less complete than a delayed study. CONCLUSIONS The reliability of barium enema after incomplete colonoscopy is less than previously reported. Poster presentation at the meeting of The American Society of Colon and Rectal Surgeons, Dallas, Texas, May 8 to 13, 2004. Reprints are not available.     

Factors associated with incomplete colonoscopy: a population-based study

BACKGROUND & AIMS: The U.S. Multi-Society Task Force on Colorectal Cancer sets a target of cecal intubation in at least 90% of colonoscopies. We conducted a population-based study to determine the colonoscopy completion rate and to identify factors associated with incomplete procedures. METHODS: Men and women 50 to 74 years of age who underwent a colonoscopy in Ontario between January 1, 1999, and December 31, 2003, were identified. The first (index) colonoscopy was classified as complete or incomplete. A generalized estimating equations model was used to evaluate the association between patient, endoscopist (specialty, colonoscopy volume), and setting (academic hospital, community hospital, private office) factors and incomplete colonoscopy. RESULTS: A total of 331,608 individuals had an index colonoscopy, of which 43,483 (13.1%) were incomplete. Patients with an incomplete colonoscopy were older (odds ratio [OR] 1.20 per 10-year increment; 95% confidence interval [CI]=1.18-1.22), more likely to be female (OR 1.35; 95% CI: 1.30-1.39), have a history of prior abdominal surgery (OR 1.07; 95% CI: 1.05-1.09) or prior pelvic surgery (OR 1.04; 95% CI: 1.01-1.06). For colonoscopies done in a private office, the odds of an incomplete procedure were more than 3-fold greater than for procedures done in an academic hospital (OR 3.57; 95% CI: 2.55-4.98). CONCLUSIONS: In usual clinical practice in Ontario, 13.1% of colonoscopies are incomplete. The factors most strongly associated with incomplete colonoscopy were increased patient age, female sex, and having the procedure in a private office. Quality improvement programs are needed to improve colonoscopy completion rates.     

The Norwegian Gastronet project: Continuous quality improvement of colonoscopy in 14 Norwegian centres

OBJECTIVE: The burden on colonoscopy capacity is considerable and expected to increase further as colorectal cancer screening programmes gain a foothold in Europe. In this situation, it is particularly important to evaluate the quality of the service given. In this article we present our first year of experience with a quality network of endoscopy centres in Norway (Gastronet). MATERIAL AND METHODS: A questionnaire focusing on caecal intubation rate and pain was completed by the endoscopist (on site) and patient (on the day after the examination). Fourteen centres participated with registration of 7370 colonoscopies by 73 endoscopists. RESULTS: There was 100% endoscopist participation, 87% coverage of colonoscopies and an estimated 76% questionnaire coverage of the patient population. Overall caecal intubation rate was 91%, range 83% to 97% between centres (p < 0.001). Patients reporting severe pain during colonoscopy differed from 2 to 24% between centres (p < 0.001). Variations could only partly be explained by differences in procedure practice (sedation, CO2 insufflation). For individual endoscopists, improvement after feedback on performance was restricted to the group of endoscopists having contributed with only 50-99 registered colonoscopies. CONCLUSIONS: In quality assurance programmes we recommend a limited number of variables for registration in order to secure high compliance by endoscopists and patients. One year of experience with Gastronet disclosed a satisfactory overall caecal intubation rate, but considerable variation between centres in practice and ability to offer painless colonoscopy. This suggests a need for formal, centralized training of colonoscopists or the development of quality standards for colonoscopy training and practice.     

Accuracy of assessment of the extent of examination by experienced colonoscopists.

One hundred colonoscopies were done. The colonoscopist noted whether the cecum had been intubated as well as the markers used to make this determination. With the colonoscope in position at maximum penetration, a radiologist independently determined its position using fluoroscopy, with a contrast agent delivered through the colonoscope. The cecum was entered in 86 of 100 cases. The tip of the colonoscope was at the level of the ileocecal valve in nine additional cases; the colonoscopist judged that the cecum was well seen in five of these nine. In one case, the colonoscopist overestimated the extent of the examination when transillumination in the right lower quadrant was the only confirming marker. When the more reliable markers (ileocecal valve, appendiceal orifice, converging indentations of the taenia coli in the cecal pole) were seen, no errors were made. Experienced colonoscopists are accurate in assessing the extent of colonoscopy and fluoroscopic confirmation is not routinely needed. When reliable markers are not seen during the examination, a barium enema, preferably with air contrast, should be done.     

Combined use of double- and single-contrast barium enema in the evaluation of suspected colonic disease

Although controversy has surrounded the use of single- and double-contrast barium enemas for many years, a growing opinion exists that these studies are complementary, each possessing advantages in different clinical settings. We have found that when interpretation of double-contrast studies is difficult because suspected abnormalities are subtle or because technical quality of examinations is less than ideal, single-contrast enemas can be helpful. We have been able to obtain high-quality single-contrast studies using low-viscosity, low-density barium suspensions administered immediately following evacuation after initial air contrast evaluation.     

Practice and documentation of performance of colonoscopy in a central Canadian health region

OBJECTIVE:

To evaluate the reporting and performance of colonoscopy in a large urban centre.

METHODS:

Colonoscopies performed between January and April 2008 in community hospitals and academic centres in the Winnipeg Regional Health Authority (Manitoba) were identified from hospital discharge databases and retrospective review of a random sample of identified charts. Information regarding reporting of colonoscopies (including bowel preparation, photodocumentation of cecum/ileum, size, site, characteristics and method of polyp removal), colonoscopy completion rates and follow-up recommendations was extracted. Colonoscopy completion rates were compared among different groups of physicians.

RESULTS:

A total of 797 colonoscopies were evaluated. Several deficiencies in reporting were identified. For example, bowel preparation quality was reported in only 20%, the agent used for bowel preparation was recorded in 50%, photodocumentation of colonoscopy completion in 6% and polyp appearance (ie, pedunculated or not) in 34%, and polyp size in 66%. Although the overall colonoscopy completion rate was 92%, there was a significant difference among physicians with varying medical specialty training and volume of procedures performed. Recommendations for follow-up procedures (barium enema, computed tomography colonography or repeat colonoscopy) were recorded for a minority of individuals with reported poor bowel preparation or incomplete colonoscopy.

CONCLUSIONS:

The present study found many deficiencies in reporting of colonoscopy in typical, city-wide clinical practices. Colonoscopy completion rates varied among different physician specialties. There is an urgent need to adopt standardized colonoscopy reporting systems in everyday practice and to provide feedback to physicians regarding deficiencies so they can be rectified.     

The effect of prior colonic imaging on endoscopic productivity: potential impact of computed tomographic colonography.

BACKGROUND & AIMS: If computed tomographic colonography (CTC) is used for primary colorectal cancer (CRC) screening with a small polyp size threshold to define a CTC study as positive, a substantial portion of all colonoscopies performed annually will be to follow up positive CTC examinations. Moreover, the majority of positive CTC examinations would be false positives (FP). This case-control study was undertaken to test the hypothesis that colonoscopy examinations resulting from FP CTC studies would take longer to complete than negative screening colonoscopies. METHODS: Endoscopic records of a large, urban hospital were reviewed to identify all patients who had either a positive barium enema (BE) study or flexible sigmoidoscopy (FS) and a negative follow-up colonoscopy examination (these patients were used as surrogates for CTC FP cases). For each of the 28 FP patients or cases identified, 2 screening colonoscopies performed by the same endoscopist within the same time period were identified and used as matched controls. A two-way analysis of variance test was performed to assess for differences in time to complete colonoscopies between these 2 groups, controlling for the individual endoscopist. RESULTS: FP colonoscopies took an average of 24.0 minutes to complete, whereas negative screening colonoscopies took 14.9 minutes; FP colonoscopies required 61% more active time to complete. This highly statistically significant difference (P < .0001) persisted with subset analyses that only included BE or FS cases and when fellow or surgeon cases were excluded. CONCLUSIONS: FP colonoscopies take longer to perform than negative screening colonoscopies. If CTC is implemented as the primary modality for CRC screening, these FP examinations could comprise a substantial percentage of the colonoscopies performed, potentially leading to a significant decrease in endoscopic productivity.     

Repeat colonoscopy’s value in gastrointestinal bleeding

AIM:To assess the diagnostic yield and clinical value of early repeat colonoscopies for indications other than colorectal cancer(CRC) screening/surveillance.METHODS:A retrospective review of patients who had more than one colonoscopy performed for the same indication within a three year time frame at our tertiary care referral hospital between January 1,2000 and January 1,2010 was conducted.Exclusion criteria included repeat colonoscopies performed for CRC screening/surveillance,poor bowel preparation,suspected complications from the index procedure,and incomplete initial procedure.Primary outcome was new endoscopic finding that led to an endoscopic therapeutic intervention or any change in clinical management.Clinical parameters including age,sex,race,interval between procedures,indication of the procedure,presenting symptoms,severity of symptoms,hemodynamic instability,duration between onset of symptoms and when the procedure was performed,change in endoscopist,withdrawal time,location of colonic lesions and improvement of quality of bowel preparation were analyzed using bivariate analysis and logistic regression analysis to examine correlation with this primary outcome.RESULTS:Among 19 772 colonoscopies performed during the above mentioned period,947 colonoscopies(4.79%) were repeat colonoscopies performed within 3 years from the index procedure.Out of these repeat colonoscopies,139 patient pairs met the inclusion criteria.The majority of repeat colonoscopies were for lower gastrointestinal bleeding(88.4%),change in bowel habits(6.4%) and abdominal pain(5%).Among 139 eligible patient pairs of colonoscopies,only repeat colonoscopies that were done for lower gastrointestinal bleeding and abdominal pain produced endoscopic findings that led to a change in management [25 out of 123(20.33%) and 2 out of 7(28.57%),respectively].When looking at only recurrent lower gastrointestinal bleeding cases,new endoscopic findings included 8 previously undetected hemorrhoid lesions(6.5%),7 actively bleeding lesions requiring endoscopic intervention,which included 3 bleeding arterio-venous malformations(2.43%),2 bleeding radiation colitis(1.6%),and 2 bleeding internal hemorrhoids(1.6%),5 previously undetected tubular adenomas [4 were smaller than 1 cm(4.9%) and 1 was larger than 1 cm(0.8%)],3 radiation colitis(2.43%),1 rectal ulcer(0.8%),and 1 previously undetected right sided colon cancer(0.8%).Of the 25 new endoscopic findings,18(72%) were found when repeat colonoscopy was done within the first year after the index procedure.These findings were 1 rectal ulcer,3 radiation colitis,4 new hemorrhoid lesions,3 previously undetected tubular adenomas,and 7 actively bleeding lesions requiring endoscopic intervention.Of all parameters analyzed,only the interval between procedures less than one year was associated with higher likelihood of finding a clinically significant change in repeat colonoscopy(odds ratios of interval between procedures of 1-2 year and 2-3 year compared to 0-1 year were 0.09;95%CI 0.01-0.74,P = 0.025 and 0.26;95%CI 0.09-0.72,P = 0.010 respectively).No complications were observed among all 139 colonoscopy pairs.CONCLUSION:There is clinical value of repeating a colonoscopy for recurrent lower gastrointestinal bleeding,especially within the first year after the index procedure.     

Racial differences in use of colonoscopy,sigmoidoscopy, and barium enema in Medicare beneficiaries

Colorectal cancer is often diagnosed at a later stage in blacks. We wanted to know if racial differences existed in the use of tests for detection of colorectal cancer. A 5% random sample was obtained of all Medicare beneficiaries with Part B coverage, aged 65 years and older and classified as white or black race. The numbers of colonoscopies, flexible sigmoidoscopies, and barium enemas were determined from the Physician/Supplier file. Blacks were 18% less likely to receive colonoscopy and 39% less likely to receive flexible sigmoidoscopy after controlling for age, sex, income, and access to care in a multivariable logistic regression model. Barium enema was not significantly different between the races. Black men had 25% lower use of colonoscopy and 50% decreased use of flexible sigmoidoscopy. Blacks receive less colonoscopy and flexible sigmoidoscopy than whites. Black men are particularly vulnerable to the under-use of these tests.     

The extent of successful colonoscopy: a second assessment using modern equipment

Records of 200 consecutive and unselected colonoscopies were reviewed to determine both the success in viewing the entire colon and the average extent of colon visualized, using the most modern equipment. Colonoscopy was completed to the cecum or ileum in 82.5% of studies, and an average of 93.8% of the colon was viewed. These data show considerable improvement compared to those previously reported by us. However, the significant number of incomplete colonoscopies still suggests that colonoscopy and barium enema examination must remain complementary for maximum detection of colonic lesions.     

Flexible sigmoidoscopy plus air contrast barium enema versus colonoscopy for suspected lower gastrointestinal bleeding

A randomized, controlled trial was performed to compare the diagnostic yields and cost-effectiveness of two strategies for the evaluation of nonemergent lower gastrointestinal bleeding. Three hundred eighty patients aged greater than or equal to 40 yr were randomized to undergo initial flexible sigmoidoscopy plus air contrast barium enema or colonoscopy; 332 completed the initial studies. Initial colonoscopy detected more cases of polyps less than 9 mm in size, adenomas, and arteriovenous malformations but fewer cases of diverticulosis. No significant difference was found between strategies in the number of patients detected with cancers or polyps greater than or equal to 9 mm in size. In both strategies, cancers were more common in subjects aged greater than or equal to 55 yr (8% overall) than in those aged less than 55 yr (1%). Among patients aged less than 55 yr with suspected lower gastrointestinal bleeding, initial flexible sigmoidoscopy plus air contrast barium enema is a more cost-effective strategy for the detection of colonic neoplasms than initial colonoscopy. However, initial colonoscopy is more cost effective for those aged greater than or equal to 55 yr.