In the 21st Century:What is the role of mechanical bowel preparation in colorectal

resection ?

Nick RiegerAssociate Professor

University of Adelaide

South Australia

Mechanical Bowel Preps

• PEG solutions

• Fleet

• Picolax

• Micro-enemas

• Enemas

• Combinations of above

What I do!

• No bowel preparation for anorectal procedures

• No bowel preparation for right sided resections and APR

• Micro-enema for restorative anterior resection

• Picolax X2 for colonoscopy• Picolax X2 for anterior

resection with planned loop ileostomy

Why?

• Mechanical bowel preparation has not been shown to have any influence for or against the technical performance of the procedure

• There is no benefit in terms of complication rates (In fact MBP may be harmful)

• MBP can have a negative effect. Hydration, electrolytes, obstruction, discomfort and inconvenience.

• HOW TO SURVIVE A BOWEL PREPMany of us have endured this process before you, and here is what we have learnt:

• Prepare yourself mentally! Decide you’re going to do it, and just do it!

• Eat lightly a couple of days before the bowel prep. Eat more fruit and green vegetables and reduce meat and dairy products. This will make it easier for your bowels to empty.

• Some find that the mixture tastes best ice cold. One way to cool it quickly is to put it in the sink with ice all around it.

• As soon as you have drunk the mixture, follow-up with something strong tasting, such as your favourite flavoured chewing gum, hard candy, or a spoonful of chicken broth to get the taste out of your mouth. Make sure whatever you follow-up with is on your physician’s list of “approved liquids”.

• At some point the mixture will begin to "work.” This may take some time. It seems to help things along if you drink approved liquids in between the "cocktails." Liquids such as ginger ale, chicken broth, lemonade, apple juice, are usually the most appealing. Remember to check with your physician for a list of what liquids are allowed.

• Use baby wipes to wipe your bottom. Get the all-natural, alcohol-free, aloe vera, unscented version. These will really save your bottom once you begin going often. If you have a tendency to develop haemorrhoids, be sure to have a haemorrhoid cream on hand. It contains a little bit of "local anaesthesia” to ease the discomfort. You’ll be happy you did so!

• If you feel yourself getting sick after drinking the umpteenth glass, try holding a sachet pillow to your nose, or a handkerchief scented with your favourite perfume or essential oil. If other drinks are allowed (check with your physician), try a slice of fresh ginger in some boiling water (ginger helps relieve nausea).

• Prepare the bathroom for your ordeal. You will spending a lot of time in there! Clean it if you think the corner fuzz balls will make you crazy after a while. Make it cosy with a bunch of flowers or some nice candles.

• Stock up on your favourite, easy-to-read books and magazines. You will need something to pass the time away.

• Station yourself near the bathroom. Make yourself a little nest that’s within a short dash to the bathroom. Have near you the TV, your books and magazines, your bowel prep cocktail, other approved liquids, pillows, and blankets. The urge to go will strike suddenly and without much warning, so be prepared for this little adventure by doing some advance planning. And try to make sure you do not have to "share" the bathroom with others during this time.

A recent case!• 70+ year old paraplegic woman admitted for

elective laparoscopic loop sigmoid colostomy• Full bowel prep performed pre-operatively in a

wheel chair bound elderly person• Hospital admission required for MBP• MBP very inconvenient for the staff and patient• Absolutely no need as the bowel is not opened at

the operation until exteriorized• Did not use bowels for 9 days postoperatively

delaying education re stoma

TEMPORARY STOMA(Ileostomy)• Dependant on:• Height of anastomosis• Ease and technical success

of operation• Well being of the patient

(co-morbidities)• Surgical conservatism• Radiation

PERMANENT STOMA(Colostomy)• Dependant on:• Height of tumour from

anal canal• Likelihood of continence

The evidence: Study 1

Guenaga et al. Mechanical bowel preparation for elective colorectal surgery. Cochrane database 2005

1159 patients with anastomosis (6 RCT)Group 1 - 576 prepGroup 2 - 583 no prep

The evidence: Study 1

OR 1.94

CI 1.09-3.43

P = 0.02

OR 1.75

CI 0.18-17.02

OR 1.17

CI 0.35-3.96

NS

17/583 (2.9%)

1/166 (0.6%)

6/50 (12%)Gp 2

32/576 (5.5%)

2/172 (1.16%)

6/48 (12.5%)

Gp 1

OverallColonicLARAnastomotic leak

The evidence: Study 1

35/609 (5.7%)

NS

0/326 (0%)

NS

Group 2

44/595 (7.4%)2/329 (0.6%)Group 1

Wound Infection

Mortality

The evidence: Study 1

No difference in:• Peritonitis, Re-operation, Infectious extra-

abdominal complication, Non-infectious extra-abdominal complication, Surgical site infection

“The results failed to support the hypothesis that bowel preparation reduces anastomotic leak rates and other complications”

The evidence : Study 2

• Wille-Jorgensen et al. Pre-operative mechanical bowel cleansing or not? An updated meta-analysis. Colorectal disease. 2005

• 1592 patients (9 RCT)

• Group 1: Bowel preparation – 789 patients

• Group 2: No bowel preparation – 803 patients

The evidence : Study 2

OR 1.72

CI 0.43-6.95

NS

OR 1.46

CI 0.97-2.18

P = 0.07

OR 2.03

CI 1.28-3.26

P = 0.003

3/516 (0.6%)

43/803 (5.4%)

25/777 (3.2%)

Group 2

No Prep

5/509 (1%)59/791 (7.4%)

48/772 (6%)Group 1

Prep

MortalityWound Infection

Leak

The evidence : Study 2

Conclusion

• “There is no evidence to that patients benefit from MBP. On the contrary taking colorectal surgery as a whole, pre-operative bowel cleansing leads to a higher rate of anastomotic leakage. The dogma that MBP is necessary before elective colorectal surgery has to be reconsidered.”

The evidence : Study 3

• Bucher et al. Mechanical bowel preparation for elective colorectal surgery: a meta-analysis. Arch Surgery 2006

• 1297 patients (7 RCT)• MBP 642 patients• No MBP 655 patients• Increased risk anastomotic leak 5.6% vs

2.8; OR 1.84; P=0.03

The evidence : Study 3

Conclusion • “There is no evidence to support the use of

Mechanical bowel preparation in patients undergoing elective colorectal surgery. Available data tend to suggest that MBP could be harmful with respect to the incidence of anastomotic leak and does not reduce the incidence of septic complications.”

Australian NHMRC Guidelines 2005

• “MBP is not indicated in elective colorectal operations unless there are anticipated problems with faecal loading that might create technical difficulties with the procedure. Eg. Laparoscopic surgery, low rectal cancers.”

• Level of evidence I• Practice recommendation – Not recommended

ASCRS 2006 Seattle

Survey • USA 99% colorectal surgeons use MBP • France 75%Abstract – France• Case controlled study for rectal cancer• 52 patients No MBP; 61 patients MBP• Postoperative morbidity overall higher (51% vs 31%, p = 0.036)• No difference leak rate• Infection trended higher (23% vs 12%; NS)• Higher infectious extra-abdominal complications (11% vs 0% ; p = 0.014)• Mean hospital stay longer (15 vs 12 days; p = 0.037)

“Fast Track Surgery”

Key Components

• Preoperative optimization

• Intraoperative attenuation of the stress response

• Postoperative restoration

“Fast Track Surgery”

Preoperative Optimization

• Medical and psychological needs

• Prehabilitation

• Postoperative N and V

• Fasting and MBP

• Explanation of perioperative trajectory

“Fast Track Surgery”

Intraoperative attenuation of the stress response

• Thoracic epidural

• IV fluid optimization

• Avoidance drains and tubes

• Minimally invasive surgery

• Aggressive Rx PONV

• Normothermia

“Fast Track Surgery”

Postoperative Care

• Multimodal analgesia

• Early oral feeding

• Early mobilization

“Fast Track Surgery”

Prehab Surgery Rehab Post-rehab

Preoperative Optimization

No Preoperative Optimization

Minimally invasive + Preoperative Optimization

Summary

• Mechanical bowel preparation belongs in the 20th century

• No evidence to support its use with elective bowel resection

• Evidence suggests that there is an increased complication rate

• MBP avoided with “fast track surgery”