ABSTRACT
The large bowel normally contains formed and solid stool, which hampers the performance
of a safe and informative lower endoscopy. The aim of mechanical bowel preparation
for colonoscopy is to rid the bowel of stool and permit adequate visualization of
the entire colonic mucosa. For flexible sigmoidoscopy, which examines only the rectum
and distal colon, cleansing of the rectosigmoid only is sufficient. Self-administered
phosphate enemas provides adequate preparation in these cases, although several authors
have advocated the addition of oral cathartic agents. However, for colonoscopy, a
pancolonic mechanical bowel preparation is required. The newest methods of bowel cleansing
with polyethylene glycol and sodium phosphate provide a high quality of preparation,
with an acceptably low morbidity rate and a high degree of patient satisfaction, in
a cost-effective manner. The current data suggest that mechanical bowel preparation
with sodium phosphate is better tolerated by the patients and is the most commonly
used preparation by colorectal surgeons for both colonoscopy and surgery. Both polyethylene
glycol and sodium phosphate are associated with electrolyte and osmolarity imbalances,
although greater changes have been found in patients who received sodium phosphate.
Thus, in patients with a history of significant renal, heart, or liver disease, polyethylene
glycol may be safer.
KEYWORD
Bowel preparation - sodium phosphate - polyethylene glycol - colonoscopy
