Predictive value of impaired evacuation at proctography in diagnosing anismus.
OBJECTIVE
We aimed to determine the positive predictive value of impaired evacuation during evacuation proctography for the subsequent diagnosis of anismus.


METHODS
Thirty-one adults with signs of impaired evacuation (defined as the inability to evacuate two thirds of a 120 mL contrast enema within 30 sec) during evacuation proctography underwent subsequent anorectal physiologic testing for anismus. A physiologic diagnosis of anismus was based on a typical clinical history of the condition combined with impaired rectal balloon expulsion or abnormal surface electromyogram.


RESULTS
Twenty-eight (90%) of the 31 patients with impaired proctographic evacuation were found to have anismus at subsequent physiologic testing. Among the 28 were all 10 patients who evacuated no contrast medium and all 11 patients with inadequate pelvic floor descent, giving evacuation proctography a positive predictive value of 90% for the diagnosis of anismus. A prominent puborectal impression was seen in only three subjects during proctography, one of whom subsequently showed no physiologic sign of anismus.


CONCLUSIONS
Impaired evacuation during evacuation proctography is highly predictive for diagnosis of anismus.
Halligan
S
S
Intestinal Imaging Centre, Level 4V, St. Mark's Hospital, Northwick Park, Watford Rd., Harrow, London, HA1 3UJ, United Kingdom.
Malouf
A
A
Bartram
C I
CI
Marshall
M
M
Hollings
N
N
Kamm
M A
MA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001004:Anus Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D001466:Barium Sulfate; D003248:Constipation / Q000000981:diagnostic imaging* / Q000209:etiology; D003287:Contrast Media; D019841:Defecography; D003937:Diagnosis, Differential; D004576:Electromyography; D004733:Enema; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests
D003287:Contrast Media; D001466:Barium Sulfate