Wiktionary
defecography
n. (context medicine English) radiography of the defecation process
Wikipedia
Defecography
Defecography (also known as proctography, defecating/defecation proctography, evacuating/evacuation proctography or dynamic rectal examination) is a type of medical radiological imaging in which the mechanics of a patient's defecation are visualized in real time using a fluoroscope. The anatomy and function of the anorectum and pelvic floor can be dynamically studied at various stages during defecation.