To explore the clinical value of mechanical bowel preparation (MBP) in preoperative management of colorectal cancer.

Prospective study were carried out from May 2017 to June 2019, including 104 patients with colorectal cancers. According to the numerical randomization method, 104 patients were randomly divided into MBP group (52 cases with preoperative MBP) and non-MBP group (52 cases without preoperative MBP). Patients in both groups underwent laparotomy for colorectal cancer by the same surgeon. Statistical analysis were performed by using SPSS 20.0 software. Measurement data such as perioperative indicators, stress response indicators and changes in intestinal flora were expressed as (±s) and were examined by using independent t test. Postoperative complications.were analyzed by using Chi-square test. A P value <0.05 was considered as statistically significant.

The first postoperative exhaust time and hospitalization time in the non-MBP group were better than those in the MBP group (P<0.05). There was no significant difference of overall incidence of postoperative complications between the two groups (P>0.05). Cor, hs-crp, il-6 and other stress indicators in the two groups were significantly increased on day 1 and day 3 after the operation compared with those before the operation respectively (P<0.05), however with significantly higher level in the MBP group than that in the non-MBP group (P<0.05). In both two groups postoperative mild to moderate intestinal flora imbalance were all observed, and Ⅱ, Ⅲ dysbacteriosis degree in the MBP group is lighter than that in the MBP group (P=0.011). BL and LC count of probiotics in the two groups was significantly lower than those before surgery, and that in the non-MBP group was higher than that in the MBP group (P<0.05). The number of EB and SP of pathogenic bacteria was significantly higher than those before operation, with lower level in non-MBP group than that in MBP group (P<0.05).

MBP before colorectal surgery could aggravate patients’ stress response and intestinal flora imbalance, however has no significant impact on reducing the incidence of postoperative infection, anastomotic fistula and other complications. Its overall clinical application value is more harmful than beneficial, and MBP before surgery is not safe and feasible.