The Diagnostic Agreement Between Digital Rectal Examination And Anorectal Manometry In The Evaluation Of Functional Constipation

ObjectiveTo evaluate agreement between digital rectal examination(DRE)and anorectal manometry(ARM)in evaluating anorectal function including sensory function in patients with functional constipation(FC),and explore the factors affecting the accuracy of diagnosis by DRE.MethodsA total of 90 patients with functional constipation who went to the department of Anorectal of Nanjing Hospital of TCM between October 2019 and December 2020 were enrolled in this study.There were 28 males and 62 females,aged 20-77 years.All patients completed several scales including Constipation Scoring System(CSS),Main Symptoms of Constipation Score,Bristol Stool form Scale and TCM syndrome differentiation form.DREs and ARM analyses were performed and recorded independently by two experienced clinical investigators under blinded conditions.The diagnostic yield of DRE compared with ARM was determined,and agreement between DRE and ARM data was evaluated.Results1.Of the 90 constipated patients,66(73.3%)were diagnosed with dyssynergia using ARM.The sensitivity,specificity,positive predictive value and negative predictive value of DRE for identifying dyssynergia were 80.3%,75.0%,89.8%and 58.1%,respectively,and moderate agreement was seen between the two diagnostic modalities(Cohen’s Kappa coefficient=0.542).Cohen’s Kappa coefficient was 0.417 when evaluating resting anal sphincter tone,and was 0.377 and 0.201 respectively in the assessment of anal maximum squeeze pressure and rectal pressure during simulated defaecation,and was only 0.136 when identifying rectal hyposensitivity.2.Age and types of TCM syndrome were proved to be main risks through logistic regression methods.Patients>60 years old and patients with deficiency syndrome appeared to have a higher risk of inaccurate diagnostic results for identifying dyssynergia on DRE(OR=5.542,95%CI:1.811,19.432;OR=4.159,95%CI:1.172,19.764).3.The anal resting pressure and the anal squeeze pressure in patients with excess syndrome were higher than those with deficiency syndrome(P<0.05).Compared with the excess syndrome group,the sustained desire to defaecate volume in patients with deficiency syndrome was significantly larger,as was the maximum tolerated volume(P<0.05).ConclusionsDRE can be used as a reliable tool for the primary diagnosis of dyssynergia.DRE has application value in assessing anorectal sphincter pressure while the accuracy of DRE in evaluating rectal sensory function seems to be poor.The patient’s age may have an influence on the accuracy of DRE.Rectal hyposensitivity is more serious in functional constipated patients with TCM deficiency syndrome than in patients with TCM excess syndrome.