Colonoscopy is an established diagnostic and therapeutic procedure performed routinely in the pediatric age group. An adequate bowel preparation is crucial for complete visualization of the large intestine and the terminal ileum. A study by Rex et al suggested that a reliable bowel cleanout regimen could significantly decrease the cost and improve the efficiency of colonoscopy in clinical practice (1). Several bowel preparations have been used in children including a large volume lavage solution and varying combinations of oral laxatives and enemas or suppositories (2–7). These bowel regimens have been found to have variable results because of limitations in their efficacy, compliance, palatability, or adverse effects.
Recently, bowel preparations based on polyethylene glycol (PEG) 3350 without electrolytes have gained popularity (8–10). PEG is an osmotic laxative that is shown to be safe and effective in the treatment of constipation and encopresis in children (11,12). We and others have reported the safety and efficacy of a 4-day bowel preparation with PEG for colonoscopy in children (8,9). A drawback of this bowel regimen has been its long duration. More recently, a retrospective study reported the safety and efficacy of a 1-day bowel preparation with PEG (10). In that study, however, children were required to drink large quantities of fluid within a short period of 2 hours. We, therefore, designed a bowel preparation regimen that could be given in less than 4 days but longer than a few hours. We increased the dose of PEG to 2 g · kg−1 · day−1 (compared with 1.5 g · kg−1 · day−1 in the 4-day bowel regimen) and added bisacodyl to improve the efficacy of the bowel preparation in spite of the shorter duration. Bisacodyl is a stimulant laxative that is safe and effective in the short term and has been used as an adjunct in several bowel preparation regimens (6,13). We performed a prospective study to evaluate the safety, efficacy, and acceptance of a 2-day bowel preparation with PEG and bisacodyl for colonoscopy in children.
PATIENTS AND METHODS
Children (ages 2.5–19 years) undergoing colonoscopy were eligible for the study. Exclusion criteria included a known allergy to PEG or bisacodyl, the presence of metabolic, renal, or cardiac disease, or an acute illness requiring an emergent colonoscopy. One hundred eleven patients were enrolled in the study from January 2008 to February 2010. The main indications for colonoscopy included abdominal pain (44%), blood in stools (18%), diarrhea (16%), follow-up endoscopic evaluation of patients with known inflammatory bowel disease (13%), growth failure (5%), and others (4%). Colonoscopies were performed in the pediatric operating room at Yale New Haven Hospital under general anesthesia using propofol. The present study was approved by the institutional review board of Yale University School of Medicine. Informed consent was obtained from parents and assent was obtained from children older than 7 years.
Patients were started on PEG 2 g · kg−1 · day−1 to a maximum of 136 g · day−1. Patients were instructed to mix 17 g (1 capful) of PEG in 240 mL of a beverage of their choice and to drink the total calculated amount in 2 to 3 divided doses daily for 2 days. A 5-mg tablet of bisacodyl was given on days 1 and 2. Because bisacodyl could not be administered in a crushed tablet form per manufacturer's recommendations, we decided to use the whole tablet (5 mg) for all of the children. Parents of younger patients were instructed to give the bisacodyl tablet to their children in a teaspoon of applesauce or yogurt. Patients were allowed a regular diet on day 1 and clear liquids on day 2. All of the patients and parents received a detailed explanation of the bowel preparation with written instructions.
Patients and parents were asked to maintain a record of the number of daily stools and the stool consistency for the duration of the bowel regimen. Stool consistency was assessed on a 1–5 scale as follows: 1, hard; 2, firm; 3, soft; 4, loose; and 5, watery. On the day of colonoscopy, patient records of stool frequency and consistency were collected. The baseline daily stool frequency and consistency during the month before the bowel regimen also were noted. Data were collected about the daily PEG dose, beverages used to prepare the PEG solution, and the palatability of the PEG solution. Patient compliance with the bowel regimen was assessed as excellent, good, fair, or poor by self-report in older children and by parent report in younger children. Ease of bowel preparation was rated as easy, okay, unpleasant, or difficult. Parents were asked to record any possible adverse effects during the bowel preparation on a scale of mild, moderate, or severe. Specific note was made of nausea, vomiting, abdominal pain, or bloating.
Adequacy of colon preparation was assessed and agreed upon by the endoscopist and an observer (endoscopy nurse or a pediatric gastroenterology fellow). Note was made regarding the level of endoscope insertion and any unusual colonic mucosal changes. Right and left colons were assessed separately as follows: excellent (presence of no stool or small amount of thin fecal fluid), good (presence of thin to thick liquid fecal matter easily removed by suction), fair (presence of thick stools requiring suction with water lavage), or poor (presence of solid stools with poor visualization of the mucosa). Colon preparations that were rated as excellent or good were considered satisfactory, whereas those rated as fair or poor were considered unsatisfactory. Satisfactory preparations allowed complete and thorough visualization of the colonic mucosa without the need for extra effort and time to clean the colon. The use of water lavage to clean the colon automatically resulted in the endoscopists rating the preparation as unsatisfactory.
The stool frequency and consistency on each day of bowel preparation were compared to values at baseline by using a paired, 2-tailed Student t test. We compared the efficacy and safety of the present 2-day bowel preparation with that of our previous regimen (8) of 4-day PEG (1.5 g · kg−1 · day−1) because patient characteristics and methodology were similar in both studies. Numerical values were expressed as mean ± SEM. Categorical data were analyzed using the Fisher exact test. A P value of <0.05 was regarded as significant.
One hundred eleven children (61 boys, 50 girls) completed the study. The mean age was 11.9 years (range 2.5–19 years). The age distribution of the children was as follows: 9 children (<5 years), 54 children (>5–13 years), and 48 children (>13 years). The weights of the children ranged from 15 to 99 kg. The average dose of PEG solution per day was 1200 mL (range 480–1920 mL). On average, children used 2 different beverages (range 1–6) to prepare the PEG solution. The beverages used were fruit juices (66), sports drinks (32), water (31), and others (35). All of the patients consumed the entire volume of the preparation orally.
A diary of bowel movements was available for all of the children. Table 1 shows the significant increase in stool frequency and stool consistency during the 2-day bowel preparation compared with baseline. All of the patients had watery stools (consistency 5 on the scale) on the second day of the bowel preparation. Figure 1 shows the assessments of the quality of colon preparation in the right and left colon. Excellent or good colon preparations (satisfactory preparations) were seen in 92% and 93% of patients in the right and left colons, respectively. The bowel preparation was rated as unsatisfactory (fair or poor) in 12 out of the 111 patients (10.8%). Only 1 patient had a poor bowel preparation because of solid stools in the right colon and the endoscopist could not advance the colonoscope beyond the transverse colon. In the other 11 patients with a fair bowel preparation, the endoscopists were able to reach the cecum or terminal ileum using water lavage. One patient had an excellent bowel preparation, but because of multiple polypectomies, a voluntary decision was made not to advance the colonoscope to the cecum. Overall, the endoscopists reached the cecum or terminal ileum in 98% of patients in the present study.
When we compared patients with satisfactory and unsatisfactory bowel preparations, there were no significant differences in different age groups or in other parameters such as sex, indication for colonoscopy, type of beverage used to mix the PEG solution, and baseline stool frequency and consistency between the 2 groups. Patients with a satisfactory bowel preparation had a significant increase in average stool frequency on both days compared to baseline (baseline 2, to 4 on day 1, to 7 on day 2: P < 0.0001 for both). Patients with unsatisfactory bowel preparations had a significant increase in average stool frequency only on day 2 compared with baseline (baseline 2, to 3 on day 1, to 5 on day 2: P = 0.16 for day 1 and P = 0.008 for day 2 compared with baseline).
We compared efficacy of the present 2-day bowel regimen with that of our previous 4-day PEG bowel regimen (8) because similar grading parameters were used in both studies. The results of the present 2-day regimen of excellent or good bowel preparations in right and left colon (92% and 93%, respectively) are similar to that of the historical 4-day regimen (right colon 91% and left colon 95%).
Patients reported adverse effects such as nausea (19%), abdominal pain (11%), and occasional vomiting (4%) during the PEG and bisacodyl bowel regimen. All of the adverse effects experienced during the 2-day bowel preparation were rated as mild by the patients. None of the patients in the study stopped the bowel regimen because of adverse effects. The mild adverse effects with the 2-day regimen were similar to those seen with the previous 4-day PEG bowel regimen (nausea 13%, abdominal pain 11%, and occasional vomiting 11%) (8). At endoscopy, we did not observe any unusual colonic mucosal changes as have been reported with sodium phosphate bowel preparations (14).
The compliance with bowel regimen was rated as excellent in 95%, good in 4%, and fair in 1% of the patients. None of the patients rated compliance as poor. The palatability of PEG solution was rated as good (81%), okay (16%), and bad (3%) by the patients. Patients reported the PEG bowel preparation to be easy (77%), okay (17%), or unpleasant (5%). Only 1 child believed that taking the bowel regimen was difficult.
In the present prospective study, we report the use of a 2-day bowel preparation with PEG and bisacodyl. The present regimen was well accepted by children with excellent compliance and none of the patients had any significant adverse effects. Moreover, the present regimen was effective in significantly increasing the stool frequency and consistency for 2 days. Using the present bowel regimen, the endoscopists were able to reach the terminal ileum or the cecum in 98% of the patients.
In our study, PEG and bisacodyl were safe and did not result in major adverse effects in our patients. The clinical adverse effects were mild and included nausea, vomiting, and abdominal pain. The compliance with our bowel regimen was excellent in 95% of children in the study. The high compliance could be the result of several factors. First, PEG is a virtually tasteless powder, making it palatable when mixed in a beverage. In addition, none of the patients had any problem taking bisacodyl. Second, we encouraged the children to mix PEG in different beverages of their choice to improve compliance. Finally, children were allowed to drink the daily PEG dose in 2 to 3 divided doses without any restriction of time. We believe that none of the patients had poor compliance with the bowel regimen because of these factors.
The present 2-day bowel regimen was effective in cleaning out the colon. On the second day, all of the children had multiple watery stools. The colon preparation was rated as satisfactory (excellent or good) in 92% of the patients in the right colon and 93% of patients in the left colon. When we compared patients with and without satisfactory colon preparations, there was no difference in age, sex, indication of colonoscopy, type of beverage used to mix the PEG solution, or baseline stool frequency and consistency in these 2 groups. The efficacy of the present 2-day bowel preparation was similar to that of our previous 4-day bowel regimen with PEG only (8). The similar efficacy was likely the result of the additional stimulant effect of bisacodyl and a slightly higher dose of PEG (2 vs 1.5 g · kg−1 · day−1), despite the shorter duration of bowel preparation.
Several other bowel regimens have been used for colonoscopies in children. Traditionally, PEG with electrolyte lavage solution has been used in children with excellent results (3,4); however, its acceptance and tolerance are limited because of its salty taste and the large volume that often requires the placement of a nasogastric tube because of nausea and vomiting (3,4). Another commonly used effective preparation is sodium phosphate (5,13–15); however, the present preparation has drawbacks of causing electrolyte abnormalities such as severe hyperphosphotemia and hypocalcemia (5,13–15) and can result in colonic mucosal changes that mimic inflammatory bowel disease (14). Bowel regimens using combinations of different medications such as magnesium citrate, bisacodyl, Fleet enemas, and pico-salax have shown variable effectiveness and problems with adverse effects (6,7,13). Recently Adamiak et al reported the efficacy and safety of a 1-day PEG bowel preparation regimen for colonoscopy in children (10). Adamiak et al did not use standard grading parameters to assess outcome measures such as compliance, tolerance, and adequacy of the bowel regimen. Additionally, the children had to drink a large volume of PEG solution (1.9 L) in a commercially available sports drink during the course of 2 hours (10). In comparison with other bowel regimens, our 2-day regimen with PEG and bisacodyl offers the advantage of excellent patient acceptance and efficacy without any major adverse effects. The present regimen can be used during the weekend in children to avoid loss of school days.
Our study had a few limitations. First, the endoscopist collecting patient data on the day of the procedure also rated the preparation. To minimize bias, we used an objective parameter while rating the bowel preparation. Bowel preparations requiring the use of water lavage for complete visualization were automatically rated as fair or poor. In addition, an observer rated the preparation along with the endoscopist. The second limitation was that we did not perform any laboratory studies in our patients to assess biochemical adverse effects related to the bowel regimen. In previous studies, high-dose PEG therapy was not associated with clinically significant changes in blood tests such as electrolyte profile, osmolality, or renal function (8,12,16). Short-term bisacodyl therapy is also tolerated well without any major adverse effects (2,6) and, therefore, the present bowel regimen is unlikely to be associated with any major biochemical adverse effects.
In summary, the present new 2-day bowel preparation with PEG and bisacodyl is safe and effective for use in children. It is also well accepted and therefore should be considered an attractive option for colonoscopy in children.
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