Evaluation of perineal descent by defaecography.

Perineal descent was studied by defaecography with the patients in the sitting position in 55 healthy volunteers, 21 women with idiopathic faecal incontinence and 8 women with obstructed defaecation. This technique provides data necessary for the evaluation of defaecation disorders, i.e. morphological changes during defaecation as well as the dynamics of the pelvic floor. It was found that the pelvic floor position during rest and during straining is almost the same in women with incontinence and in women with obstructed defaecation. Furthermore patients with normal position of the pelvic floor during rest may exhibit considerable descent during straining while patients with abnormal position of the perineum during rest may show normal descent during straining. This observation may indicate that the first sign of abnormal function may be an increased descent during straining, only later following by descent during rest. The importance of establishing control data is emphasized since differences in defaecographic techniques between different centres may render comparison difficult.