The recommended dose for adults is 4 liters of polyethylene glycol 3350 and electrolytes for oral solution prior to gastrointestinal examination, as ingestion of this dose produces a satisfactory preparation in over 95% of patients. Ideally, the patient should fast for approximately 3 or 4 hours prior to polyethylene glycol 3350 and electrolytes for oral solution administration, but in no case should solid food be given for at least 2 hours before the solution is given.
Polyethylene glycol 3350 and electrolytes for oral solution is usually administered orally, but may be given via nasogastric tube to patients who are unwilling or unable to drink the solution. Oral administration is at a rate of 240 mL (8 oz.) every 10 minutes, until 4 liters are consumed or the rectal effluent is clear. Rapid drinking of each portion is preferred to drinking small amounts continuously. Nasogastric tube administration is at a rate of 20 to 30 mL per minute (1.2 to 1.8 liters per hour). The first bowel movement should occur approximately one hour after the start of polyethylene glycol 3350 and electrolytes for oral solution administration.
Various regimens have been used. One method is to schedule patients for examination in midmorning or later, allowing the patients 3 hours for drinking and an additional one hour period for complete bowel evacuation. Another method is to administer polyethylene glycol 3350 and electrolytes for oral solution on the evening before the examination, particularly if the patient is to have a barium enema.
Preparation of the solution
Polyethylene glycol 3350 and electrolytes for oral solution is prepared by filling the container to the 4 liter mark with water and shaking vigorously several times to insure that the ingredients are dissolved. Dissolution is facilitated by using lukewarm water. The solution is more palatable if chilled before administration. The reconstituted solution should be refrigerated and used within 48 hours. Discard any unused portion.