MRI defecography is a dynamic MRI test that images the pelvic floor and bowel during rest, squeezing and evacuation. It uses contrast gel in the rectum and sequences taken while the patient simulates or actually evacuates on an MRI‑compatible commode. The study assesses anorectal anatomy and function—rectocele, enterocele, intussusception, pelvic organ prolapse, sphincter defects and pelvic floor descent—without ionising radiation.

An MRI defecography typically takes about 20–45 minutes in total. Preparation and positioning add time, while the dynamic imaging portion—capturing pelvic floor movement during evacuation—usually lasts around 10–20 minutes. Exact duration varies by facility, the number of sequences or views needed, and whether contrast is used. Allow extra time for arrival, consent, and changing clothes.

In MRI defecography the patient lies supine (on their back) inside the scanner, usually with hips and knees flexed and feet supported on a brace or wedge to permit pelvic‑floor movement. Rectal (and sometimes vaginal) gel is inserted; the patient is asked to rest, squeeze, then strain and evacuate during dynamic image sequences. Some centers use open/upright MRI to mimic a seated position.

Defecography is usually ordered by a colorectal surgeon, gastroenterologist, pelvic‑floor specialist or urogynecologist; primary care physicians or physiotherapists may also refer patients. Radiologists perform the study. It’s requested to evaluate chronic constipation, obstructed defecation, fecal incontinence, suspected rectal prolapse or pelvic‑floor dysfunction, and when other tests haven’t explained persistent anorectal symptoms.

A doctor orders defecography to evaluate anorectal and pelvic floor function during evacuation when patients report chronic constipation, straining, a sensation of incomplete emptying, or fecal incontinence. It detects structural problems—rectocele, rectal prolapse, intussusception—and functional disorders like pelvic floor dyssynergia. Findings guide treatment or surgical planning for refractory bowel symptoms or suspected anatomical causes.

To prepare for defecography: follow a low‑residue diet 24–48 hours before, avoid laxatives unless instructed, and empty your bowels (you may be asked to use a small enema at home or at the clinic). Wear comfortable clothes, bring a towel or pad, continue essential medications, and remove vaginal pessaries. Inform staff if pregnant, breastfeeding, or allergic to contrast, and follow facility instructions.