The introduction of a new radiological method requires the assessment of the advantage-risk ratio. On measuring the radiation doses during defecography, skin entrance and gonadal exposure values were found to be lower than during well-known and well-established examinations of the small pelvis, such as colon enema and CT of the lower abdomen. Defecography, as a radiological tool for diagnosing the anorectal function is, therefore, also suitable for young persons.