Polyethylene glycol (PEG) has gained a reputation as safe and well tolerated¹ method of bowel preparation for colonoscopy, colonic surgery, radiological examination, and faecal dysimpaction in intractable constipation. PEG 3350 is a chemically inert polymer of formula H(OCH₂CH2)_n where n = 68–84 with negligible (<0.06%) gastrointestinal tract absorption in normal subjects. This limits the potential for systemic toxicity.² PEG causes a substantial flow of faecal water by osmosis, and because volumes required for bowel cleansing are larger than many patients can comfortably drink, it is frequently given through a nasogastric tube.

Reported side effects include transient nausea and vomiting, abdominal fullness, cramps, and anal irritation. Allergic reactions have been reported rarely. Extra care is advised in patients with impaired gag …