Introduction A number of factors including gender, smoking, radiotherapy, and length of surgery have traditionally been associated with a higher risk of developing anastamotic leak. However, recent studies have indicated that unprepared bowel does not increase the incidence of anastamotic leaks. The aim of this study was to see if the introduction of a ‘no bowel preparation’policy in our unit impacted on leak rates.

Method A retrospective review of all cases undergoing colorectal resections between May 2006 and May 2011 were included in this study. An Enhanced Recovery Programme was introduced in April 2010 for all colorectal patients and as part of this left sided colorectal resections received a phosphate enema instead of a full mechanical bowel preparation. Right hemicolectomy patients did not receive any bowel preparation throughout the study period.

Results 514 colorectal resections were performed during the study period. Of these, 30 patients had an anastomotic leak, 5.9% were following right hemicolectomy, 1.9% following left hemicolectomy or sigmoid colectomy and 11.7% following anterior resection. Following the introduction of ‘no bowel preparation’ policy, the leak rate was unchanged for left hemicolectomy and sigmoid colectomy. However, we found a marked increase in leak rates following anterior resections from 6.6% to 20% (p value = 0.023). A defunctioning ileostomy appeared to reduce the effects of the anastomotic leak and all of these (n = 5) were managed conservatively with no mortality compared to those without ileostomy, the majority of whom required a laparotomy and had a mortality rate of 16.6%. The overall elective mortality was 5.8%.

Conclusion The Introduction of a no bowel preparation policy resulted in a significant increase in anastomotic leak rates following anterior resections. Therefore, we recommend the use of full mechanical bowel preparation for rectal surgery. Use of a covering ileostomy should be considered in high risk patients.

Disclosure of interest None Declared.