Bowel preparation
From Ganfyd
Bowel preparation is the use of various oral laxatives to clear out the bowel in preparation for lower GI surgery or other bowel investigation, e.g. colonoscopy or barium enema.
The need for bowel preparation in bowel investigations is obvious as faecal residue affects the quality of imaging of colonoscopy, barium enema and CT colonography (though there is research into developing CT colonography without bowel preparation.
On the other hand, the need for bowel preparation prior to lower GI surgery is less clear. Traditionally, bowel preparation was thought to reduce bacterial contamination and therefore reduce anastomotic leak and wound infection, but the convincing evidence that it is beneficial is surprisingly sparse.[1][2][3]
Recent studies[4] show that not only may it not be beneficial, but it may be harmful as bowel preparation could actually be detrimental as bowel prep irritates the bowel, deprives patients of nutrition prior to the operation and can cause dehydration and electrolyte disturbance.
In one study, oral sodium phosphate solution given in preparation for colonoscopy was associated with a small, but lasting deterioration in renal function.[5]
Contraindicated in suspected bowel obstruction. Intravenous fluids may be useful in elderly patients as significant amount of electrolyte and water can be lost.
Most of the pharmacological agents used in bowel preparation are osmotic purgatives. As they progress along the bowel, they draw water in creating, in effect, an iatrogenic diarrhoea. Patients need to drink adequate amounts of water for the preparations to work optimally.
Examples
- Picolax
- Sodium picosulphate and magnesium citrate.
- Fleet Phospho-soda
- Phosphate salts - sodium dihydrogen phosphate and others .
- Klean-Prep
- PEG and other salts, e.g. sodium sulphate, sodium bicarbonate, NaCl, KCl.
- Moviprep
References
- ↑ Guenaga KF, Matos D, Castro AA, Atallah AN, Wille-Jørgensen P. Mechanical bowel preparation for elective colorectal surgery. Cochrane Database Syst Rev. 2005 Jan 25;(1):CD001544.
- ↑ Wille-Jørgensen P, Guenaga KF, Matos D, Castro AA. Pre-operative mechanical bowel cleansing or not? an updated meta-analysis. Colorectal disease : the official journal of the Association of Coloproctology of Great Britain and Ireland. 2005;7:304-10. (Direct link – subscription may be required.)
- ↑ Jung B, Pahlman L, Nystrom PO, Nilsson E; Mechanical Bowel Preparation Study Group. Multicentre randomized clinical trial of mechanical bowel preparation in elective colonic resection. Br J Surg. 2007 Jun;94(6):689-95. (Direct link - subscription may be required.)
- ↑ Fa-Si-Oen P, Roumen R, Buitenweg J, van de Velde C, van Geldere D, Putter H, et al. Mechanical bowel preparation or not? Outcome of a multicenter, randomized trial in elective open colon surgery. Diseases of the colon and rectum. 2005;48:1509-16. (Direct link – subscription may be required.)
- ↑ Khurana A, McLean L, Atkinson S, Foulks CJ. The effect of oral sodium phosphate drug products on renal function in adults undergoing bowel endoscopy. Archives of internal medicine. 2008 Mar 24; 168(6):593-7.(Link to article – subscription may be required.)
