Diagnostic value of balloon expulsion test and anorectal manometry in patients with constipation: a systematic review and meta-analysis

This study aims to compare the diagnostic value of balloon expulsion test and anorectal manometry in patients with constipation through meta-analysis. Databases, encompassing PubMed, EMBASE, Cochrane Library, Web of Science, etc. were searched for all English publications on the diagnosis of constipation using balloon expulsion test and anorectal manometry. The publication date was restricted from the inception of the databases until December 2022. Data analysis was carried out utilizing Stata 15.0 and Meta-Disc 1.4 software. Thirteen studies involving 2171 patients with constipation were included. According to the meta-analysis, the balloon expulsion test showed a pooled sensitivity of 0.75 (95% CI: 0.72–0.77), a pooled specificity (Spe) of 0.67 (95% CI: 0.62–0.72), a pooled positive likelihood ratio (+LR) of 3.24 (95% CI: 1.53–6.88), a pooled negative likelihood ratio (−LR) 0.35 (95% CI: 0.23–0.52) and a pooled diagnostic odds ratio (DOR) of 9.47 (95% CI: 3.27–27.44). For anorectal manometry, the pooled Sen, Spe, +LR, −LR and DOR were 0.74 (95% CI: 0.72–0.76), 0.73 (95% CI: 0.70–0.76), 2.69 (95% CI: 2.18–3.32), 0.35 (95% CI: 0.28–0.43), and 8.3 (95% CI: 5.4–12.75), respectively. The area under the summary receiver operating characteristic curve areas for balloon expulsion test and anorectal manometry were 0.8123 and 0.8088, respectively, with no statistically significant disparity (Z = −0.113, P > 0.05). Both the balloon expulsion test and anorectal manometry demonstrate comparable diagnostic performance, each offering unique advantages. These diagnostic procedures hold significance in the diagnosis of constipation.