Proctographic features of anismus.
OBJECTIVE
To document the proctographic features of anismus at evacuation proctography and determine the optimum radiologic measurements for diagnosis.


METHODS
Twenty-four patients with anismus according to clinical and multiple physiologic criteria were examined with evacuation proctography. Structural and functional measurements were compared with those of a group of 20 asymptomatic subjects.


RESULTS
No significant difference between patients and control subjects was found with respect to pelvic descent, rectocele, or any anorectal angle measurement. In patients with anismus, initiation of evacuation was prolonged (median, 9 vs 3 seconds for control subjects; P < .0001) and anal canal width was reduced (median, 0.6 vs 1.2 cm; P = .0075). Evacuation time was increased (median, 50 vs 10 seconds; P < .0001), and the percentage of contrast material evacuated was decreased (median, 60% vs 100%; P < .0001). Only four patients were able to evacuate more than 66% of the contrast material within 30 seconds, whereas all control subjects were able to do so.


CONCLUSIONS
Measurement of the anorectal angle to diagnose anismus should be abandoned. Patients with anismus demonstrate delayed initiation of evacuation, which is also prolonged and incomplete. Incomplete evacuation after 30 seconds is highly suggestive of anismus.
D000328:Adult; D000368:Aged; D001003:Anal Canal / Q000000981:diagnostic imaging*; D001004:Anus Diseases / Q000000981:diagnostic imaging; D001466:Barium Sulfate; D016022:Case-Control Studies; D002933:Cineradiography; D003287:Contrast Media; D003672:Defecation; D003937:Diagnosis, Differential; D005260:Female; D005471:Fluoroscopy; D006547:Hernia / Q000000981:diagnostic imaging; D006801:Humans; D007418:Intestinal Pseudo-Obstruction / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012002:Rectal Diseases / Q000000981:diagnostic imaging*; D012007:Rectum / Q000000981:diagnostic imaging; D013997:Time Factors
D003287:Contrast Media; D001466:Barium Sulfate