Gastroenterology and Hepatology

Bowel Prep

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All the information provided here including recommendations and suggestions should be treated for informational purposes only and not a coercion to follow.
The author should not be held liable for any informational errors, incompleteness, delays or for any actions taken in reliance on information contained here.

Ideal bowel prep should:

Reliably empty the colon

Doesn’t cause gross or histologic alteration of the colonic mucosa

No patient discomfort

No shifts in fluids / electrolytes



Diet restriction: Clear liquids and low residue diet for 1-4 days





Nonabsorbable solution.

No food 2 hours prior

240ml every 10 min till rectal output clear or 4 L consumed

<5 hours before procedure is best. >19 hours poor.

Addition of Bisacodyl to 4L PEG is not useful

Preferred in renal, liver, CCF patients


Other regimes of PEG:

2-3 L the night before colonoscopy then 1-2 L morning of the procedure

Low volume PEG (2L) in the evening preceeded by 1 day CF with 4 tab Bisacodyl at noon



Low volume hyperosmotic solution

Significant fluid and electrolyte shifts

CF 1 day and 45cc 2 times 10-12 hours apart (eg: 6pm and 6am)


Tablet NaP

32-40 tablets. (20 tab evening before and 12-20 tab on the day of the procedure, 3-5 hours before procedure)

Taken 4 tab every 15 minutes with 240ml fluids


Making sure solutions are consumed:

Mix with flavouring agents

Use Ryle’s Tube


Risk of poor prep:


Food to avoid: