0016-5107/92/3803 -0369$03.00 GASTROINTESTINAL ENDOSCOPY Copyright © 1992 by the American Society for Gastrointestinal Endoscopy
Addition of enemas to oral lavage preparation for colonoscopy is not necessary Eric L. Lever, MD, Michael H. Walter, Stanley C. Condon, MD, Kumaravelu Balasubramaniam, Yang K. Chen, MD, Robert D. Mitchell, Raymond Herber, MD, Martin J. Collen,
MD MD MD MD
Lama Linda, California
To evaluate whether the addition of enemas to oral electrolyte lavage is helpful for colonoscopic preparation, we conducted a prospective, randomized, observerblinded trial to compare oral lavage plus enemas with oral lavage alone. The quality of preparation, mucosal visualization, and the volume of retained colonic fluid did not differ between the two groups. Twenty-two percent of the patients in the group who received oral lavage plus enemas compared with 12% of the patients in the group that only received oral lavage stated that they would refuse to repeat the preparation for future colonoscopic examination. Seventeen percent of the patients in the group that received oral lavage plus enemas demonstrated anorectal trauma or inflammation compared with only 5% in the group that received oral lavage alone (p = 0.09). These results indicate that the addition of enemas to oral lavage preparation for colonoscopic evaluation cannot be routinely recommended. However, enemas may be considered on an individual basis in the occasional patient unable to consume the complete oral lavage or in whom residual stool is found during colonoscopic evaluation after oral lavage preparation. (Gastrointest Endosc 1992;38:369-372)
Since the availability of oral electrolyte lavage solutions containing polyethylene glycol in 1980,1 oral electrolyte lavage has become a popular method of colonic preparation for colonoscopy. Although many variations are used in practice, two methods of colonic preparation are recommended in the standard endoscopic literature. 2 Oral lavage method using electrolyte solution with polyethylene glycol has been shown to have superior effectiveness and patient acceptance compared with the alternate regimen of fasting, laxatives, and enemas. 3- 6 Many colonoscopists utilize enemas in addition to oral electrolyte lavage for colonoscopic preparation. However, other than anecdotal experience, there are no data to justify the addition of enemas to oral electrolyte lavage. In our study, we prospectively investigated the quality of preparation Received August 1, 1991. For revision October 2, 1991. Accepted December 26, 1991. From the Department of Medicine, Division of Gastroenterology, Loma Linda University Medical Center, Loma Linda, California. Reprint requests: Martin J. Collen, MD, Division of Gastroenterology #111G, Jerry L. Pettis Memorial Veterans Hospital, 11201 Benton Street, Loma Linda, California 92357. VOLUME 38, NO. 3, 1992
and patient acceptance of oral electrolyte lavage with or without enemas. MATERIALS AND METHODS Patients
Over a 6-month period, 116 patients who were scheduled for elective colonoscopy as outpatients were prospectively evaluated for this study. In order to qualify, patients had to be 18 years of age or older, scheduled for elective colonoscopy, and able to tolerate oral electrolyte lavage and enemas. Eligible patients were randomized by the nursing staff to one of the two treatment groups, given colonic preparation instructions, and scheduled for the colonoscopy. Colyte® (Reed and Carnrick Pharmaceuticals, Piscataway, N. J.) oral electrolyte solution containing 60 g of polyethylene glycol 3350 in 4-liter containers was provided to each patient at the time of randomization. Enema delivery apparatus was also provided at that time for those randomized to receive enemas. Investigations
Patients in both treatment groups were advised to begin a liquid diet the morning before the colonoscopy. At 4 p.m. 369
in the afternoon, prior to the scheduled colonoscopy, both groups were advised to drink the oral lavage solution at a rate of 8 oz every 15 min until completion, for a total duration of 4 hours or less. After the oral lavage preparation, they were advised to drink only water. The patients randomized to the group that were to receive enemas were instructed to take the enemas the morning of the colonoscopic examination. They were instructed to use tap water enemas of at least 500 ml each in succession until clear water returned. The colonoscopist was blinded as to the preparation group. When the patient arrived for the colonoscopic examination, each patient completed a questionnaire regarding the preparation undertaken and their perception of the colonoscopic preparation. Following the colonoscopy, the colonoscopist completed a data sheet detailing indications and findings. Each rated the quality of preparation for each of four segments of the colon (ascending, transverse, descending, and rectosigmoid) on a standard scale of 1 to 5 (Table 1) and judged the visualization in each segment as "optimal" if more than 80% of the mucosa in that segment could be visualized or as "suboptimal" if less than 80% was visualized. The volume of water used for lavage during the procedure and the total volume aspirated during the procedure were recorded by the nurse assisting with the colonoscopy. For analysis, the amount of retained fluid in the colon was calculated by subtracting the volume used for lavage from the total fluid aspirated during the colonoscopy. Statistics and informed consent
Student's t test and Fisher's exact test were used for statistical evaluation of data where appropriate. Student's t test was used to analyze the continuous variables such as quality of preparation and volume of retained fluid, and Fisher's exact test was used to analyze the dichotomous variables such as visualization and presence or absence of anorectal trauma. Differences were considered to be statistically significant when p < 0.05. 7 Power was analyzed for the quality of preparation by considering a difference of 1 on the standard scale of 1 to 5 as significant. The power for detecting a quality of preparation difference of 1 on the standard scale between the means of the two treatment groups was greater than 99%. The protocol was approved by the Institutional Review Board of Loma Linda University Medical Center. Written informed consent was obtained from each patient at the time of randomization.
RESULTS A total of 116 patients were randomized and entered into the trial. Colonoscopic examination was completed and data were obtained in 82 patients. The characteristics of the two sample groups are outlined in Table 2. There were no significant differences between the two groups with respect to age, gender, the volume of oral lavage electrolyte solution consumed, duration of consumption, or the diet on the day before the examination. No patient consumed less than 2 liters of oral lavage preparation. There were no significant differences between the two groups with respect to the indications for colonoscopy (Table 3). The patients who had the enema preparation took a mean of 2.0 enemas. No patient in the group that took oral lavage alone took enemas. The mean quality of preparation score was 4 or greater in each colonic segment for both groups (Table 1). There were no significant differences in quality of preparation score between the two groups in any colonic segment. The mean total score (summation of all colonic segments) for the group that received oral lavage plus enemas was slightly higher than that for the group that received only oral lavage, 4.45 and 4.28, respectively. Preparation quality did not correlate with volume of oral Table 2. Characteristics of the 82 patients who received colonoscopic preparation Characteristics Age (mean, yr) Gender (M/F) Amount oral lavage consumed ~3 liter
Addition of enemas to oral lavage preparation for colonoscopy is not necessary Eric L. Lever, MD, Michael H. Walter, Stanley C. Condon, MD, Kumaravelu Balasubramaniam, Yang K. Chen, MD, Robert D. Mitchell, Raymond Herber, MD, Martin J. Collen,
MD MD MD MD
Lama Linda, California
To evaluate whether the addition of enemas to oral electrolyte lavage is helpful for colonoscopic preparation, we conducted a prospective, randomized, observerblinded trial to compare oral lavage plus enemas with oral lavage alone. The quality of preparation, mucosal visualization, and the volume of retained colonic fluid did not differ between the two groups. Twenty-two percent of the patients in the group who received oral lavage plus enemas compared with 12% of the patients in the group that only received oral lavage stated that they would refuse to repeat the preparation for future colonoscopic examination. Seventeen percent of the patients in the group that received oral lavage plus enemas demonstrated anorectal trauma or inflammation compared with only 5% in the group that received oral lavage alone (p = 0.09). These results indicate that the addition of enemas to oral lavage preparation for colonoscopic evaluation cannot be routinely recommended. However, enemas may be considered on an individual basis in the occasional patient unable to consume the complete oral lavage or in whom residual stool is found during colonoscopic evaluation after oral lavage preparation. (Gastrointest Endosc 1992;38:369-372)
Since the availability of oral electrolyte lavage solutions containing polyethylene glycol in 1980,1 oral electrolyte lavage has become a popular method of colonic preparation for colonoscopy. Although many variations are used in practice, two methods of colonic preparation are recommended in the standard endoscopic literature. 2 Oral lavage method using electrolyte solution with polyethylene glycol has been shown to have superior effectiveness and patient acceptance compared with the alternate regimen of fasting, laxatives, and enemas. 3- 6 Many colonoscopists utilize enemas in addition to oral electrolyte lavage for colonoscopic preparation. However, other than anecdotal experience, there are no data to justify the addition of enemas to oral electrolyte lavage. In our study, we prospectively investigated the quality of preparation Received August 1, 1991. For revision October 2, 1991. Accepted December 26, 1991. From the Department of Medicine, Division of Gastroenterology, Loma Linda University Medical Center, Loma Linda, California. Reprint requests: Martin J. Collen, MD, Division of Gastroenterology #111G, Jerry L. Pettis Memorial Veterans Hospital, 11201 Benton Street, Loma Linda, California 92357. VOLUME 38, NO. 3, 1992
and patient acceptance of oral electrolyte lavage with or without enemas. MATERIALS AND METHODS Patients
Over a 6-month period, 116 patients who were scheduled for elective colonoscopy as outpatients were prospectively evaluated for this study. In order to qualify, patients had to be 18 years of age or older, scheduled for elective colonoscopy, and able to tolerate oral electrolyte lavage and enemas. Eligible patients were randomized by the nursing staff to one of the two treatment groups, given colonic preparation instructions, and scheduled for the colonoscopy. Colyte® (Reed and Carnrick Pharmaceuticals, Piscataway, N. J.) oral electrolyte solution containing 60 g of polyethylene glycol 3350 in 4-liter containers was provided to each patient at the time of randomization. Enema delivery apparatus was also provided at that time for those randomized to receive enemas. Investigations
Patients in both treatment groups were advised to begin a liquid diet the morning before the colonoscopy. At 4 p.m. 369
in the afternoon, prior to the scheduled colonoscopy, both groups were advised to drink the oral lavage solution at a rate of 8 oz every 15 min until completion, for a total duration of 4 hours or less. After the oral lavage preparation, they were advised to drink only water. The patients randomized to the group that were to receive enemas were instructed to take the enemas the morning of the colonoscopic examination. They were instructed to use tap water enemas of at least 500 ml each in succession until clear water returned. The colonoscopist was blinded as to the preparation group. When the patient arrived for the colonoscopic examination, each patient completed a questionnaire regarding the preparation undertaken and their perception of the colonoscopic preparation. Following the colonoscopy, the colonoscopist completed a data sheet detailing indications and findings. Each rated the quality of preparation for each of four segments of the colon (ascending, transverse, descending, and rectosigmoid) on a standard scale of 1 to 5 (Table 1) and judged the visualization in each segment as "optimal" if more than 80% of the mucosa in that segment could be visualized or as "suboptimal" if less than 80% was visualized. The volume of water used for lavage during the procedure and the total volume aspirated during the procedure were recorded by the nurse assisting with the colonoscopy. For analysis, the amount of retained fluid in the colon was calculated by subtracting the volume used for lavage from the total fluid aspirated during the colonoscopy. Statistics and informed consent
Student's t test and Fisher's exact test were used for statistical evaluation of data where appropriate. Student's t test was used to analyze the continuous variables such as quality of preparation and volume of retained fluid, and Fisher's exact test was used to analyze the dichotomous variables such as visualization and presence or absence of anorectal trauma. Differences were considered to be statistically significant when p < 0.05. 7 Power was analyzed for the quality of preparation by considering a difference of 1 on the standard scale of 1 to 5 as significant. The power for detecting a quality of preparation difference of 1 on the standard scale between the means of the two treatment groups was greater than 99%. The protocol was approved by the Institutional Review Board of Loma Linda University Medical Center. Written informed consent was obtained from each patient at the time of randomization.
RESULTS A total of 116 patients were randomized and entered into the trial. Colonoscopic examination was completed and data were obtained in 82 patients. The characteristics of the two sample groups are outlined in Table 2. There were no significant differences between the two groups with respect to age, gender, the volume of oral lavage electrolyte solution consumed, duration of consumption, or the diet on the day before the examination. No patient consumed less than 2 liters of oral lavage preparation. There were no significant differences between the two groups with respect to the indications for colonoscopy (Table 3). The patients who had the enema preparation took a mean of 2.0 enemas. No patient in the group that took oral lavage alone took enemas. The mean quality of preparation score was 4 or greater in each colonic segment for both groups (Table 1). There were no significant differences in quality of preparation score between the two groups in any colonic segment. The mean total score (summation of all colonic segments) for the group that received oral lavage plus enemas was slightly higher than that for the group that received only oral lavage, 4.45 and 4.28, respectively. Preparation quality did not correlate with volume of oral Table 2. Characteristics of the 82 patients who received colonoscopic preparation Characteristics Age (mean, yr) Gender (M/F) Amount oral lavage consumed ~3 liter
