Magnetic resonance defecography findings of dyssynergic defecation.

Dyssynergic defecation (DD) is defined as paradoxical contraction or inadequate relaxation of the pelvic floor muscles during defecation, which causes functional constipation. Along with the anal manometry and balloon expulsion tests, magnetic resonance (MR) defecography is widely used to diagnose or rule out pelvic dyssynergia. Besides the functional abnormality, structural pathologies like rectocele, rectal intussusception, or rectal prolapse accompanying DD can also be well demonstrated by MR defecography. This examination can be an uncomfortable experience for the patient, so the imaging method and the importance of patient cooperation must be explained in detail. The defecatory phase of the examination is indispensable for evaluation, and inadequate effort should be ruled out before diagnosing DD. MR defecography provides important data for the diagnosis of DD, but optimal imaging criteria should be applied. Further tests can be suggested if patient co-operation is not sufficient or MR defecography findings are irrelevant.