Background: Bowel preparation prior to colonic surgery usually includes antibiotic therapy together with mechanical bowel preparation (MBP). Mechanical bowel preparation may cause discomfort to the patient, prolonged hospitalization, and water and electrolyte imbalance. It was assumed that with the improvement in surgical technique together with the use of more effective prophylactic antibiotics, it was possible that MBP would no longer be necessary.Hypothesis: There is no statistical difference in the postoperative results of patients who undergo elective colon resection with MBP as compared with those who have no MBP. Design and Patients:The study includes all patients who had elective large bowel resection at Campus Golda between April 1, 1999, and March 31, 2002. Emergency operations were not included. The patients were randomly assigned to the 2 study groups (with or without MBP) according to identification numbers. All patients were treated with intravenous and oral antibiotics prior to surgery. The patients in the MBP group received Soffodex for bowel preparation.Results: A total of 329 patients participated in the study, 165 without MBP and 164 with MBP. The 2 groups were similar in age, sex, and type of surgical procedure. Two hundred sixty-eight patients (81.5%) underwent surgery owing to colorectal cancer and 61 patients (18.5%) owing to benign disease. The hospitalization period was longer in the bowel-prepared group (mean ± SD, 8.2 ± 5.1 days) as compared with the nonprepared group (mean±SD, 8.0±2.7 days). However, this difference was not statistically significant. The time until the first bowel movement was similar between the 2 groups: a mean±SD of 4.2±1.3 days in the nonprepared group as compared with a mean±SD of 4.3±1.1 days in the prepared group (P =NS). Four patients (1.2%) died in the postoperative course owing to acute myocardial infarction and pulmonary embolism. Sixty-two patients (37.6%) of the non-MBP group suffered from postoperative complications as compared with 77 patients (46.9%) of the MBP group. Conclusion:Our results suggest that no advantage is gained by preoperative MBP in elective colorectal surgery.

Lateral internal sphincterotomy caused a significant decline in the resting anal pressure. During the first year following surgery, the tone of the internal anal sphincter gradually increased, indicating recovery, but still remained significantly lower than before surgery. However, postoperative resting pressures were higher than those in the control, and no patient suffered any permanent problems with incontinence, so this decrease may not be clinically significant.

The early of pelvic irradiation on the anal sphincter has not been previously investigated. This study prospectively evaluated the acute effect of preoperative radiation on anal function. Twenty patients with rectal carcinoma received 4,500 cGy of preoperative external beam radiation. The field of radiation included the sphincter in 10 patients and was delivered above the anorectal ring in 10 patients. Anal manometry and transrectal ultrasound were performed before and four weeks after radiotherapy. No significant difference in mean maximal squeeze or resting pressure was found after radiation therapy. An increase in mean minimal sensory threshold was significant. Histologic examination revealed minimal radiation changes at the distal margin in 8 of 10 patients who underwent low anterior resection and in 1 of 3 patients who underwent abdominoperineal resection. We conclude that preoperative radiation therapy has minimal immediate effect on the anal sphincter and is not a major contributing factor to postoperative incontinence in patients after sphincter-saving operations for rectal cancer.

The purpose of this study was to investigate the effect of general anesthesia and surgery on melatonin production, and to assess the relationship between melatonin secretion and cortisol levels. Twenty (9 males and 11 females) consecutive otherwise healthy patients aged 27 to 52 years were included in this study. The patients underwent laparoscopic cholecystectomy or laparoscopic hernioplasty. All patients had general anesthesia with the same anesthetic drugs. Serum cortisol levels were measured at several time periods. Urine collections for melatonin were performed from 18:00 to 7:00 the day prior to surgery, on the operation day, and on the first postoperative day. Baseline melatonin metabolites were measured the night prior to surgery, and the level was found to be 1979 +/- 1.76 ng. The value decreased to 1802 +/- 1.82 ng (NS) on the night of surgery, and it became a significantly higher, reaching 2981 +/- 1.55 ng the night after surgery (p = .003). The baseline daytime cortisol level was significantly lower than the baseline night cortisol level (6.87 +/- 1.51 microg/dl, 14.89 +/- 1.66 micrograms/dl, respectively, p < 0.0001). Surgery induced a significant increase in both day and night cortisol levels. Daytime cortisol levels increased from 6.89 +/- 1.51 microg/dl to 16.90 +/- 1.27microg/dl (p < 0.0001), whereas right levels increased from 14.89 +/- 1.66 microg/dl to 29.20 +/- 1.24 microg/ dl (p <0.0001). The morning after surgery, cortisol levels decreased to 10.16 +/- 1.40 microg/dl, lower than the value obtained on the day of surgery (p < 0.0001). As was true of melatonin, cortisol levels did not reach the pre operative level (p < 0.005). The finding of the current study is that melatonin and cortisol levels show an inverse correlation after surgery.