To grade anismus by echodefecography (EDF) based on standard anismus grading by anorectal manometry (ARM), and analyze the correlation between the grade of anismus and the clinical symptoms of constipation.

Ninety-seven patients diagnosed with anismus were collected from December 2018 to December 2021 at the Anorectal Treatment Center of The Second Affiliated Hospital of Nanjing University of Chinese Medicine. After providing informed consent, the patients underwent ARM, chronic constipation severity scale (CSS) evaluation, and EDF. First, the patient showing abnormal contractions on anorectal manometry were scored on the CSS scale, and then EDF was performed. Anismus was then graded by EDF. On this basis, Logistic regression analysis was conducted for the anismus grade of patients and their constipation symptoms.

The following regression equation was obtained by linear regression analysis: y=0.586x-1.191 (P＜0.05). According to the CSS, anismus was graded by EDF as follows: mild, 1°＜ɑ≤5°; moderate, 5°＜ɑ≤10°; severe, 10°＜ɑ≤16°. Logistic regression analysis demonstrated that there was no significant correlation between anismus grade and patients' self-defecation, defecation frequency, anal pendant expansion, or abdominal (distension) pain (P＞0.05). However, anismus grade had a strong correlation with symptoms such as sense of bowel movement, defecation obstruction, and sense of defecation failure (P＜0.05).

Anismus grade evaluated by EDF is associated with clinical symptoms of anismus, such as bowel movement, defecation obstruction, and sense of defecation failure, which suggests that EDF is an effective method to diagnose anismus. The sample size of this study was small, so further larger-sample multi-center study is needed to determine its value.