Table 3 Optional investigations for the evaluation of deep infiltrating endometriosis.

Investigation	Evidence provided
Proctosigmoidoscopy	External impression, mucosal involvement (rare), differential diagnosis of primary bowel disease
Magnetic resonance imaging	Involvement of the bowel wall, the bladder; adenomyosis?
Transrectal endoscopic ultrasound	Involvement of the bowel wall?
Contrast enema	Bowel involvement in higher sections
Intravenous pyelogram or computed tomography	Ureteral stenosis, hydronephrosis
Cystoscopy	Bladder involvement