The aims of bowel cleansing techniques are:
- clearance of the bowel of faecal material
- reduction of bacterial flora
Bowel cleansing is achieved with a combination of the following:
- dietary restriction: the patient is usually admitted 3 days prior to surgery and placed on a low fibre, low residue diet. 24 hours prior to surgery the patient is then placed on only free fluids.
- use of purgatives: laxatives such as picolax may be given the morning before surgery, and a second dose the afternoon before surgery. Care should be taken however if there is risk of perforation.
- bowel enemas and distal bowel washouts: washouts should be continued until evacuation is clear
- bowel sterilisations - this is performed on occassion with non-absorbed oral antibacterial agents, e.g. neomycin. These are necessary if mannitol is used in order to prevent bacterial fermentation and gas formation - diathermy may trigger an explosion.
Great care should be taken when using purgatives in the presence of bowel obstruction as there is a risk of perforating the bowel. In cases of complete obstruction, only distal washouts and enemas can be given.