Defecography in contemporary coloproctological diagnostics

Evacuatory difficulty is a common problem covering a large spectrum of disorders, from constipation to faecal incontinence. In addition to a visit to a surgeon-proctologist, the diagnosis of impaired defecation often requires urological and gynaecological evaluation. Many pathologies causing evacuatory difficulty, such as full thickness rectal prolapse, reduced sphincter tone and haemorrhoidal disease, can be detected by clinicians already at the stage of physical examination. A large group of pathologies may be detected using standard diagnostic techniques such as colonoscopy and pelvic imaging, e.g. computed tomography, magnetic resonance, and transabdominal/transrectal/transvaginal ultrasonography. However, certain abnormalities are only visible during functional pelvic examination. These include rectocele, sigmoidocele, enterocele, internal intussusception, cystocele, and spastic pelvic floor syndrome. Defecography is guided by either X-ray or MRI. Pelvic function may be also assessed using transperineal ultrasonography. Defecography involves 4 phases: rest, forced contraction, strain, and defecation. The anorectal angle and, in the case of MRI, the PCL line (which is a reference point for most measurements), are determined in order to evaluate the position and mobility of pelvic organs. Pelvic function evaluation helps differentiate patients with evacuatory difficulties requiring surgical intervention from those who need conservative treatment (exercises, electrostimulation). Furthermore, it helps choose an appropriate technique and surgical access, as well as select patients requiring a more interdisciplinary approach.