• Adult patients undergoing elective colonic and upper rectum laparoscopic surgery requiring an anastomosis, without the need of conversion

General:

• < 18 years of age
• Pregnancy or breast feeding

Medical:

• Psychiatric pathology capable of affecting comprehension and judgment faculty
• History of inflammatory bowel disease
• Chronic vascular disease affecting the intestines
• Chronic constipation (<= 2 bowel movements/week)
• Previous abdominal or pelvic radiation treatment
• Recent (< 3 months before inclusion) or current intra-abdominal infection or inflammation (e.g. diverticulitis, appendicitis, cholecystitis)
• Use of gut motility influencing agents (e.g. tricyclic antidepressants, chronic use of laxatives)
• Use of nitrates (e.g. isosorbide dinitrate, nitroglycerin), including daily consumption of beetroot juice (unless stopped for a month prior to the intervention period)
• Hypotension (< 100/60 mmHg)
• Uncontrolled diabetes mellitus
• Renal or hepatic insufficiency
• Known allergies or intolerances to beetroot, nitrates/nitrites
• Enrollment in other clinical trials/experiments, unless approved by the Ethics Committee(s)

Surgical:

• History of prior colorectal surgery
• Emergency surgery
• Open surgery
• Colorectal surgery not requiring an anastomosis (e.g. colotomy, wedge resection)
• More than 1 bowel anastomosis planned
• Concomitant surgical procedures required (e.g. resection of liver or lung metastases)
• Protective stoma planned