Please select the eligibility criteria that correspond to the clinical trial below.
Title: Prophylatic Effect of Preoperative Antibiotics With Mechanical Bowel Preparation Compare With Simple Mechanical Bowel Preparation Before Laparoscopic Colorectal Surgery: a Randomized Controlled Trial
Brief Summary: Surgical site infection (SSI) is a major postoperative complication after abdominal surgery especially in colorectal field, which significantly increases length of stay (LOS), readmission incidence and expense. Therefore, identification of the effective method to reduce SSI incidence is critically important. Combination of oral antibiotics and mechanical bowel preparation was reported with lower SSIs and LOS in some retrospecitve data analysis, however a prospective randmized controlled trial was absent. Herein, the current randomized controlled trial comparing MBP+OA with MBP alone in postoperative complications in order to guide clinical practise was conducted.


Options:
A: Inclusion Criteria:

* undergoing elective colon surgery for benign or malignant disease
* over the age of 18 years
* provides informed consent.

Exclusion Criteria:

* known anaphylaxis to neomycin or metronidazole
* pregnancy or lactation
* chronic renal failure (serum creatinine \> 220 umol/L).
B: Inclusion Criteria:

* Older than 18 years old，
* Undergoing laparoscopic colorectal surgery due to malignancy.

Exclusion Criteria:

* No elective surgery
* Intra-abdominal infection
* Combination of other infectious surgery such as appendectomy, cholecystomy
* Sever comobidity such as uncontrolled hypertention and diabetes mellitus
* Peritoneal implantation and matastasis
* Radiotherapy history.
* Colorectal surgery due to benign lesions
* Allergic to antibiotics or PEG
* Preoperative dermatosis may interfere wound healing
* Long time application of corticosteroid
* Autoimmune disease may affect wound healing
* Patients refuse to enroll
C: Inclusion Criteria:

* Patients scheduled for anterior rectal resection with primary anastomosis

Exclusion Criteria:

* Emergency operation
* Bowel obstruction
* Existing stoma
* Other reason preventing mechanical bowel preparation
* Allergy to neomycin or metronidazole
* Age \< 18 years
* Lack of co-operation

Exclusion criteria after randomization:

* Patient did not undergo surgery
* Anterior resection was not performed
* Colonic anastomosis was not performed
D: Inclusion Criteria:

* Elective colon and rectal cancer surgery with primary anastomosis
* Or elective colorectal surgery for suspected carcinoma
* No evidence of distant metastases (preoperative CT-abdomen and X-thorax or CTthorax)
* Procedure either with or without diverting stoma
* Both laparoscopic and open surgery
* Informed consent
* Aged 18 years or older

Exclusion Criteria:

* Previous colorectal malignancy
* Current malignancy which is now undergoing treatment
* Inflammatory bowel disease (Crohn's disease or ulcerative colitis)
* Previous surgery for diverticular disease
* Performance status ASA 4 or higher (American Society for Anaesthesiologists)
* Expected adverse reactions/allergies for study medication
* Prednisone use \> 5 mg per day
* Familial adenomatous polyposis coli (FAP; Lynch syndrome), Hereditary Non Polyposis Colorectal Cancer (HNPCC)
* Mental disorder/unable to give informed consent
* Pregnancy

Answer: B