OBJECTIVETo discuss the clinical value and application range of defecography, CT and MRI in diagnosis of puborectalis syndrome (PRS).

METHODSThe clinical data of 83 PRS patients, including defecography, CT and MRI scanning in pelvic floor resting and defecation at maximum exertion, measurement of anorectal angle (ARA), length and depth of ARA impression and the thickness of the puborectalis muscle, were collected, and compared with those of 56 normal persons.

RESULTSFor normal persons, ARA at maximum exertion was more significantly increased than that at resting. In 62 cases with PRS, ARA at maximum exertion was more obviously reduced than that at resting and associated with puborectalis muscle (PRM) impression. In the other 21 cases, ARA showed no changes at either maximum exertion or resting, a little or no excretion of barium appeared and "shelving syndrome" was showed. The cross-sectional images of CT and MRI showed that the puborectalis of PRS patients were thicker than that of normal persons (P<0.01). PRS patients also showed clear pelvic floor muscle, fasciae and peripheral crevice.

CONCLUSIONSDefecography, manifested the abnormal function of the puborectalis muscles, is a reliable method for diagnosis of PRS. In the meantime, CT and MRI are able to clearly display the position, growth status and size of the puborectalis muscles as well as its relation with adjacent structures, which provide further understandings on anatomical changes, abnormal adjacent structure and other functional diseases of pelvic floor in PRS patients. Therefore, an appropriate combination of the 3 methods play an important role in the early diagnosis of PRS and guidance for surgical treatment.