Value Of Urgent Colonoscopy In Diagnosis Of Severe Acute Lower Gastrointestinal Bleeding In Patients With Different Bowel Cleanliness

Background and AimsSevere acute lower gastrointestinal bleeding(SALGIB)is one of the common clinical diseases in gastroenterology department and the incidence of it appears to be on the rise.Colonoscopy is usually considered to be the preferred initial test for SALGIB.However,the timing of colonoscopy(urgent colonoscopy or elective colonoscopy)remains controversial and the effect of different bowel preparation on urgent or elective colonoscopy is not clear yet.The specific objectives of this study were to compare the value of urgent colonoscopy and elective colonoscopy through analyzing the impact of different timing of colonoscopy on diagnostic rate,on the basis of which,to investigate the optimal bowel preparation before examination.Besides,we compared the difference of clinical outcomes,such as the lengths of stay/cost between urgent colonoscopy and elective colonoscopy,and described the distribution of causes about severe acute lower gastrointestinal bleeding.MethodsThe clinical data were collected retrospectively from patients who were admitted with SALGIB from June 2004 to March 2015 and underwent a colonoscopy.Patients were grouped into urgent group and elective group,depending on the timing of colonoscopy after admission.Univariate analysis was used to assess the effect of different timing of colonoscopy on diagnostic rate of hemorrhage,and a multivariate model which stratified based on cleanliness was used to analyze the impact of bowel cleanliness on diagnostic rate of urgent colonoscopy.Besides,clinical outcomes between urgent and elective group were compared and predictors of the lengths of stay and cost were explored.The etiology of SALGIB was described by descriptive analysis.Result1.According to inclusion and exclusion criteria,188 patients were eventually identified in the study.There were 118 patients in urgent group and 70 patients in elective group.Moreover,the proportion of the patients taking oral laxatives was significantly lower in urgent group(19.5%vs.77.1%,P<0.001).2.The diagnostic rates were comparable between urgent and elective groups(44.1%vs.41.4%,P=0.724).However,urgent colonoscopy resulted in a significantly higher diagnostic rate for identifying the bleeding source(32.2%vs.18.6%,P=0.041).While,the success rate of ileocecal intubation was lower in urgent group(66.9%vs.78.6%,P=0.089)and the rate of repeated colonoscopy was higher(30.5%vs.14.3%,P=0.012)compared with elective group.3.In term of cleanliness,Oral laxatives versus enema resulted in good,moderate,and poor bowel cleanliness in 63.6%vs.13.5%,28.6%vs.24.3%,and 7.8%vs.62.2%of the patients(P<0.001).4.Univariate analysis indicated that good bowel cleanliness was associated with a significantly higher diagnostic rate of colonoscopy than poor bowel cleanliness(P=0.012).In multivariate logistic model,the analysis of interaction effect between the group and the cleanliness indicated that with good bowel cleanliness,urgent colonoscopy yielded a significantly higher diagnostic rate than elective colonoscopy(P=0.030).Subgroup analyses suggested that good bowel cleanliness improved the diagnostic rate of urgent group significantly as compared with poor bowel cleanliness(P=0.015).5.The rate of patients who underwent surgery(P=0.001)and the cost(P=0.003)in urgent group was much higher than elective group.There was a trend towards longer length of stay(P=0.574)in the urgent group,although this difference was not statistically significant.Furthermore,in Cox regression model,surgery,repeated colonoscopy and blood requirement after admission were associated with a significantly increase of lengths of stay.In Linear regression analysis model,advanced age,surgery,repeated colonoscopy and volume of blood transfusion after admission were associated with a significantly increase of hospital cost.6.The distribution of etiology:Regardless of post-polypectomy bleeding(PPB),a total of 127 patients(67.6%)were discharged with clear diagnosis.Colorectal cancer and diverticulosis were the most common causes of bleeding,accounting for 8.5%respectively.The following etiologies were colorectal ulcer and inflammatory bowel disease,accounting for 8%respectively.Approximately the etiology in 18.6%of the patients was considered to be a small bowel source of bleeding.Conclusion1.In patients with good bowel cleanliness,urgent colonoscopy yields a higher diagnostic rate than elective colonoscopy for severe acute lower gastrointestinal bleeding.2.Oral laxatives is helpful to improve the rate of good bowel cleanliness,and poor bowel cleanliness resulting from bowel preparation by enema significantly lowers the diagnostic performance of urgent colonoscopy,leading to unnecessary repeated colonoscopy,or even longer length of stay.Therefore,oral laxatives are recommended over enemas before the performance of urgent colonoscopy when the patients have stable hemodynamics.3.Except post-polypectomy bleeding(PPB),the most common etiologies of SALGIB are colorectal cancer,colonic diverticulosis,colorectal ulcer and inflammatory bowel disease.