Comparison Of The Effect Of Regular Diet And Low-fiber Diet On Bowel Cleanliness Before Colonoscopy

?Background? Colorectal cancer(CRC)is one of the most common malignancies,and ranks the third in cancer incidence in the world.Colonoscopy is an important method for the diagnosis and treatment of early CRC.High-quality bowel preparation can improve the insertion rate of ileocecus and adenoma detection rate(ADR),while inadequate bowel preparation can lead to lesions being covered by feces,resulting in missed diagnosis and interrupted examination.Good bowel cleanliness is essential for the accuracy and safety of colonoscopy,and diet preparation before colonoscopy is one of the important factors affecting the quality of bowel preparation.The guidelines recommend a low-fiber diet for the day before the examination to achieve high-quality bowel preparation.However,some studies have shown that low fiber diet can lead to decreased energy intake and increased gastrointestinal response,resulting in fatigue,dizziness and hypoglycemia,leading to decreased patients' compliance with colonoscopy.It has also been pointed out that there is no significant difference in the bowel cleanliness between regular diet and clear liquid diet.Therefore,we suppose that the quality of bowel preparation of regular diet is not inferior to that of low-fiber diet,and that the regular diet can reduce the adverse reactions caused by dietary restrictions,which can improve patients' compliance and comfort.?Objective?The aim of this study was to explore the effect of regular diet on patients' bowel cleanliness before colonoscopy,and find out a more comfortable diet preparation plan for patients undergoing colonoscopy.?Methods?This was a prospective,randomized and non-inferiority clinical trial.A total of400 patients(18-75 years old)undergoing colonoscopy during March to July 2019 at the Sixth Affiliated Hospital of Guangzhou Medical University were enrolled in this study and randomly divided into regular diet group or low-fiber diet group.On the day before the colonoscopy,patients in the regular diet group were allowed to have a regular diet without any restriction,while patients in the low-fiber diet group were instructed to have a low-fiber diet(fiber < 10g/d).All patients received 3 sachets of Polyethylene glycol electrolyte(PEG),which were dissolved in 3 L water: 2 L PEG solution was consumed at 8:00 PM before theday of colonoscopy and the remaining 1 L PEG solution was consumed at 5:00 AM on the day of colonoscopy.All colonoscopies were performed within 4 to 6 h after finishing the remaining 1L PEG.The bowel preparation score,bubble scale,dietary satisfaction,polyp detection rate(PDR)and ADR in the two groups were collected and analyzed.?Results?Data were collected from 357 patients(175 in the regular diet group and 182 in the low-fiber diet group),including 174 males and 183 females,with a median age of 49(40,57).In the per-protocol(PP)population,there was no significant difference in adequate bowel preparation rate,bubble scale,diet satisfaction,PDR and ADR(P>0.05)between the two groups.Same results were found in the intention-to-treat(ITT)population.The incidence of hunger in the regular diet group was lower than that in the low-fiber group(P<0.05),and there were no significant differences in the incidence of total adverse events and other adverse events between the two groups(P>0.05).When the patients were divided into subgroups according to their ages,medical status(inpatient and outpatient)and gender,no significant differences were observed in terms of adequate bowel preparation rate,bubble scale,dietary satisfaction,PDR and ADR between each pared.In PP population,the incidences of hunger in young patients,hospitalized patients and male patients in the regular diet group were also lower than those in the low-fiber diet group(P<0.05),while in ITT population,the incidences of hunger in outpatients and female patients in the regular diet group were lower than those in the low-fiber diet group(P<0.05).In multivariate analysis,low-fiber diet was an independent risk factor for incidence of hunger(P<0.05,OR>1).There were neither significant differences between each pared in terms of the number,size and location of polyp(P>0.05).?Conclusion?Regular diet can achieve high-quality bowel preparation,improve ADR.In addition,it leads low incidence of adverse events and excellent patients' compliance.Therefore,it can be recommended as a routine program of bowel preparation before colonoscopy.