***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background A number of studies with conflicting results have evaluated the effect of chewing gum on post-operative gastrointestinal recovery in patients after major colorectal surgery . Objective The objective of the study was to study the efficacy of chewing gum in patients with rectal cancer after elective open proctectomy only . Methods A r and omized controlled clinical trial was performed . We recruited patients who would undergo elective open proctectomy for rectal cancer in Sichuan Academy of Medical Sciences and Sichuan Provincial People 's Hospital . Patients in the intervention arm received chewing gum 3 times a day postoperatively . All patients in the trial were placed on the same perioperative management and st and ardized post-operative care plans . The primary outcome was time to the first peristalsis sounds , time to first flatus and the first defecation . Results A total of 89 patients were recruited . The time to the first flatus was 42.33 ± 3.46 h in the gum group and 49.20 ± 1.42 h in the control group ( p < 0.05 ) . The time to the first defecation was significantly shorter in the gum-chewing group than in the control group ( 66.07 ± 2.36 vs. 78.37 ± 1.62 h ; p < 0.05 ) . Post-operative ileus ( POI ) was confirmed in 2 patients in the gum-chewing group and in 7 in the control group ( 7.0 % vs. 23.9 % ; p = 0.028 ) . Discussion The present study suggests that chewing gum is a method to reduce the time to first flatus , time to first defecation and POI in patients undergoing elective open proctectomy for rectal cancer BACKGROUND : Prolonged intestinal paralysis can be a problem after gastrointestinal surgery . Several systematic review s and meta-analyses have suggested the efficacy of gum chewing for the prevention of postoperative ileus . OBJECTIVE : The purpose of this study was to examine the efficacy of gum chewing for the recovery of bowel function  after surgery for left-sided colorectal cancer and to determine the physiological mechanism underlying the effect of gum chewing on bowel function . DESIGN : This was a single-center , placebo-controlled , parallel-group , prospect i ve r and omized trial . SETTING S : The study was conducted at a general hospital in Japan . PATIENTS : Forty-eight patients with left-sided colorectal cancer were included . INTERVENTIONS : The patients were r and omly assigned to a gum group ( N = 25 ) and a control group ( N = 23 ) . Four patients in the gum group and 1 in the control group were subsequently excluded because of difficulties in continuing the trial , result ing in the analysis of 21 and 22 patients in the respective groups . Patients in the gum group chewed commercial gum 3 times a day for ≥5 minutes each time from postoperative day 1 to the first day of food intake . MAIN OUTCOME MEASURES : The time to first flatus and first bowel movement after the operation were recorded , and the colonic transit time was measured . Gut hormones ( gastrin , des-acyl ghrelin , motilin , and serotonin ) were measured preoperatively , perioperatively , and on postoperative days 1 , 3 , 5 , 7 , and 10 . RESULTS : Gum chewing did not significantly shorten the time to the first flatus ( 53 ± 2 vs 49 ± 26 hours ; p = 0.481 ; gum vs control group ) , time to first bowel movement ( 94 ± 44 vs 109 ± 34 hours ; p = 0.234 ) , or the colonic transit time ( 88 ± 28 vs 88 ± 21 hours ; p = 0.968 ) . However , gum chewing significantly increased the serum levels of des-acyl ghrelin and gastrin . LIMITATIONS : The main limitation was a greater rate of complications than anticipated , which limited the significance of the findings . CONCLUSIONS : Gum chewing changed the serum levels of des-acyl ghrelin and gastrin , but we were unable to demonstrate an effect on the recovery of bowel function HYPOTHESIS Gum chewing after elective open colon resection may stimulate bowel motility and decrease duration of postoperative ileus . DESIGN AND SETTING Prospect i ve , r and omized study in a community-based teaching hospital . PATIENTS Thirty-four patients undergoing elective open sigmoid resections for recurrent diverticulitis or cancer . MAIN OUTCOME MEASURES First feelings of hunger , time to first flatus , time to first bowel movement , length of hospital stay , and complications . RESULTS A total of 34 patients were r and omized into 2 groups : a gum-chewing group ( n = 17 ) or a control group ( n = 17 ) . The patients in the gum-chewing group chewed sugarless gum 3 times daily for 1 hour each time until discharge . Patient demographics , intraoperative , and postoperative care were equivalent between the 2 groups . All gum-chewing patients tolerated the gum . The first passage of flatus occurred on postoperative hour 65.4 in the gum-chewing group and on hour 80.2 in the control group ( P = .05 ) . The first bowel movement occurred on postoperative hour 63.2 in the gum-chewing group and on hour 89.4 in the control group ( P = .04 ) . The first feelings of hunger were felt on postoperative hour 63.5 in the gum-chewing group and on hour 72.8 in the control group ( P = .27 ) . There were no major complications in either group . The total length of hospital stay was shorter in the gum-chewing group ( day 4.3 ) than in the control group ( day 6.8 ) , ( P = .01 ) . CONCLUSIONS Gum chewing speeds recovery after elective open sigmoid resection by stimulating bowel motility . Gum chewing is an inexpensive and helpful adjunct to postoperative care after colectomy BACKGROUND Postoperative ileus generates a high impact on morbidity , hospital stay , and costs . OBJECTIVE To study the efficiency and safety of chewing gum to decrease postoperative ileus in colorectal surgery . METHOD A r and omized controlled trial was performed including 64 patients who underwent elective colorectal surgery with primary anastomosis in a tertiary referral center . Patients were divided in two groups : ( i ) A : gum chewing group ( n = 32 ) , and ( ii ) B : patients who had st and ard postoperative recovery ( n = 32 ) . RESULTS Postoperative ileus was observed in 6 % ( 2/32 ) of the gum-chewing group and in 21.8 % ( 7/32 ) in the st and ard postoperative recovery group , with an odds ratio of 0.167 ( 95 % CI : 0.37 - 0.75 ; p = 0.006 ) . Vomiting was present in two patients from group A and in eight from group B ( 6.25 vs. 25.0 % ; p = 0.03 ) . Passage of flatus within the first 48 hours was present in 30 patients from group A and in 20 from group B ( 94 vs. 63 % ; p = 0.002 ) . There was earlier oral feeding ( 96 ± 53 vs. 117 ± 65 hours ; p= 0.164 ) and a shorter length of hospital stay ( 7 ± 5 vs. 9 ± 5 days ; p= 0.26 ) in the gum-chewing group ( p N.S. ) . CONCLUSIONS The use of chewing gum after colorectal surgery was associated with less postoperative ileus and vomiting , and with an increased passage of flatus within the first 48 hours after surgery . Since gum chewing is an inexpensive procedure and is not associated with higher morbidity , it can be safely used for a faster postoperative recovery in elective colorectal surgery BACKGROUND Postoperative ileus limits early hospital discharge for patients who have undergone laparoscopic procedures . Sham feeding has been reported to enhance bowel motility . Here , the effect of gum chewing is evaluated as a convenient method to enhance postoperative recovery from ileus after laparoscopic colectomy . STUDY DESIGN A total of 19 patients who underwent elective laparoscopic colectomy for colorectal cancer participated in the study . Each patient was r and omly assigned to one of two groups : a gum-chewing group ( n = 10 , mean age 58.6 years , range 50 to 71 years ) or a control group ( n = 9 , mean age 60.6 years , range 45 to 80 years ) . The patients in the gum-chewing group chewed gum three times a day from the first postoperative AM until oral intake . The times of the first passage of flatus and defecation were recorded precisely . RESULTS The first passage of flatus was seen , on average , on postoperative day 2.1 in the gum-chewing group and on day 3.2 in the control group ( p < 0.01 ) . The first defecation was 2.7 days sooner in the gum-chewing group ( postoperative day 3.1 ) than in the control group ( 5.8 days ; p < 0.01 ) . All patients tolerated gum chewing on the first operative AM . The postoperative hospital stays for the gum-chewing and control groups were 13.5+/-3.0 days and 14.5+/-6.1 days , respectively . CONCLUSIONS Gum chewing aids early recovery from postoperative ileus and is an inexpensive and physiologic method for stimulating bowel motility . Gum chewing should be added as an adjunct treatment in postoperative care because it might contribute to shorter hospital stays Objective : Prolonged ileus — the failure of postoperative ileus to resolve within a few days after major abdominal surgery — leads to significant medical consequences for the patient and costs to the hospital system . The aim of this retrospective analysis of prospect ively collected data was to identify independent preoperative and intraoperative risk factors for prolonged ileus in a large consecutive series of patients who had undergone resection for colorectal cancer . Methods : Patients were drawn from a hospital registry of 2400 consecutive resections over the period 1995–2009 . Thirty-four potential predictors of prolonged ileus were analyzed by logistic regression . Results : Prolonged ileus occurred in 14.0 % of patients . Statistically significant independent predictors of prolonged ileus were male sex ( OR : 1.7 , P < 0.001 ) , peripheral vascular disease ( OR : 1.8 , P < 0.001 ) , respiratory comorbidity ( OR : 1.6 , P < 0.001 ) , resection at urgent operation ( OR : 2.2 , P < 0.001 ) , perioperative transfusion ( OR : 1.6 , P < 0.010 ) , stoma constructed ( OR : 1.4 , P < 0.001 ) , and operation lasting ≥3 hours ( OR : 1.6 , P < 0.001 ) . Conclusions : These features can be used to alert medical and nursing staff to patients likely to experience prolonged ileus after bowel resection so that they can be monitored closely in the postoperative period and available treatments targeted toward them . These features may also be useful in the research context to facilitate the more efficient selection of high-risk patients as subjects in clinical trials of prevention or treatment Objective : The aim of this trial was to investigate whether a routine of allowing normal food at will increases morbidity after major upper gastrointestinal ( GI ) surgery . Summary Background Data : Nil-by-mouth with enteral tube feeding is widely practice d for several days after major upper GI surgery . After other abdominal operations , normal food at will has been shown to be safe and to improve gut function . Methods : Patients were r and omly assigned to a routine of nil-by-mouth and enteral tube feeding by needle-catheter jejunostomy ( ETF group ) or normal food at will from the first day after major upper GI surgery . Primary end point was rate of major complications and death . Secondary outcomes were minor complications and adverse events , bowel function , and length of stay . All patients were invited to a follow-up at 8 weeks after discharge from the hospital . Results : Four hundred fifty-three patients who underwent major open upper GI surgery in 5 centers were enrolled between 2001 and 2006 . Four hundred forty-seven patients were correctly r and omized . Of 227 patients 76 ( 33.5 % ) had major complications in the ETF group compared with 62 ( 28.2 % ) of 220 patients allowed normal food at will ( P = 0.26 , 95 % CI for the difference in rate from −3.3 to 13.9 ) . In the ETF group , 36 ( 15.9 % ) patients were reoperated compared with 29 ( 13.2 % ) in the group allowed normal food at will ( P = 0.50 ) and 30-day mortality was 10 ( 4.4 % ) of 227 and 11 ( 5.0 % ) of 220 patients , respectively ( P = 0.83 ) . Time to resumed bowel function was significantly in favor of allowing normal food at will ( P = 0.01 ) , as were the total number of major 
    Output:
    
The use of chewing gum after colorectal surgery is a safe and effective intervention in reducing the incidence of POI and merits routine use alongside other ERAS pathways in the postoperative setting