Optimizing diagnosis in obstructed defecation syndrome: A review of imaging modalities

Table 1 Key differences between imaging modalities

	FD	MRD	PFUS	EDF
Oral contrast	Needed for small bowel evaluation	Not needed	Not needed	Not needed
Ionizing radiation exposure	Yes	No	No	No
Position	Sitting on the commode	Mainly supine	Lithotomy	Left lateral
Multiplanar assessment	Limited	Excellent	Good	Good
Multicompartment diagnosis	Yes (limited)	Yes	Yes	Yes
Soft tissue assessment	No	Excellent	Good	Good
Cost	Relatively less expensive	More expensive	Low	Low

FD: Fluoroscopic defecography; MRD: Magnetic resonance defecography; PFUS: Pelvic floor ultrasound; EDF: Echodefecography.