The effect of diets delivered into the gastrointestinal tract on gut motility after colorectal surgery—a systematic review and meta-analysis of randomised controlled trials

Despite best practice guidelines, feeding methods after colorectal surgery vary due to the difficulties translating evidence into practice. The aim was to determine the effectiveness of diets delivered into the gastrointestinal tract (GIT) on gut motility following colorectal surgery. EMBASE, MEDLINE, CINAHL, Web of Science and PubMed were systematically searched. Randomised controlled trials investigating effectiveness of a diet on gut motility after colorectal surgeries were included. Outcomes included postoperative ileus, length of stay, mortality, nausea and vomiting. A total of 756 potential studies were identified; of these, 10 trials reporting on 1237 unique patients were included. There is evidence that early feeding reduces time (days) to first flatus (mean difference (MD):−0.64; 95% CI:−0.84 to −0.44) and bowel movements (MD:−0.64; 95% CI:−1.01 to −0.26), when compared to traditional postoperative fasting. Introducing solids versus the progression of fluids to solids had no effect on time (days) to first flatus (MD:0.13; 95% CI:−1.99 to 1.74) or bowel movement (MD:0.20; 95% CI:−0.50 to 0.98). Complete nutrition compared to hypocaloric nutrition had no effect on time to first flatus (MD:−0.60; 95% CI:−1.66 to 0.46) or bowel movement (MD:−0.20; 95% CI:−1.59 to 1.19), whereas coffee and diet compared to water and diet significantly decreased time (days) to first bowel movement (MD:−0.60; 95% CI:−0.97 to −0.19) but had no effect on time to first flatus (MD:−0.20; 95% CI:−0.57 to 0.09). Any form of early postoperative diet provided into the GIT early after colorectal surgery is likely to stimulate gut motility, resulting in earlier return of bowel function and shorter length of stay.