Defaecography is used in patients with symptoms of obstructive defaecation to assess this more formally. It can either be performed as conventional defaecography, which employs X-ray images, or more recently using MRI. Both tests assess the physical process of defaecation using images.
MR defaecography involves an MRI scan, during which a small amount of gel is inserted through the anal canal into the rectum. With the patient in the scanner, they are asked to expel the gel; during this process, scans are taken. This allows the radiologists to assess the rectum and surrounding structures to determine what happens when the patient attempts to empty the rectum. The findings on the scan enable your surgeon to plan future treatment, which might involve biofeedback (bowel re-training), or surgery.