Pelvic floor and rectal prolapse conditions have greatly benefitted by new imaging and instrumental diagnostic approaches, and especially defecography, for both pathophysiological interpretation and differential diagnosis. We investigated the efficacy of defecography in the assessment of rectal prolapse, and in particular the role of videoproctography in diagnosing such dynamic disorders.We selected 224 patients with rectal prolapse from a series of 1,190 consecutive subjects with evacuation disturbances examined in the last 5 years with defecography combined with videoproctography. The patients were 176 women and 48 men ranging in age 32-79 years (mean: 48). Defecography was carried out with Mahieu's technique, but we changed the filter position slightly. Sixty-seven per cent of our patients had been submitted to sigmoidoscopy, but this examination does not usually show rectal intussusception. Occult blood test in feces and double contrast barium enema were carried out in 42% and 38% of cases, respectively, to exclude any organic conditions of colon.Mucosal prolapse was more frequent than intussusception (71% and 34%, respectively); rectal walls went out through the anus in 12 cases of anorectal intussusception and thus caused external rectal prolapse. Rectal prolapse was associated with other anorectal alterations, such as rectocele, perineal descent and puborectalis muscle syndrome, in 96 cases.The dynamic changes of ampulla are well depicted by videoproctography, which showed anorectum normalization and spontaneous reduction of invagination after intussusception. Defecography exhibited good capabilities in showing rectal wall function abnormalities. Finally, some features of videoproctography such as low radiation dose, noninvasiveness and ease of execution, make the examination acceptable to patients with anorectal disorders and for the follow-up of rectal prolapse.