eTable 3. Known classification systems for diverticular disease/diverticulitis.

	Classification of Diverticular Disease (CDD) (4)		Modified Hinchey classification (e31)		Hansen-Stock classification (e32)
	Type	Definition	Stage	Definition	Stage	Definition
Asymptomatic diverticulosis	Type 0	Identification of diverticula in the colon	x	–	0	Identification of diverticula in the colon
Acute uncomplicated diverticulitis	Type 1a	Diverticulitis without peridiverticulitis	0	Diverticulitis without peridiverticulitis	I	Diverticulitis without peridiverticulitis
	Type 1b	Diverticulitis with phlegmonous peridiverticulitis	Ia	Diverticulitis with phlegmonous peridiverticulitis
Acute complicated diverticulitis	Type 2a	Divertikulitis with microabscess (≤ 1cm); minimal paracolic air	Ib	Diverticulitis with paracolic abscess	IIa	Diverticulitis with phlegmonous peridiverticulitis
	Type 2b	Diverticulitis with macroabscess (> 1cm)	II	Diverticulitis with distant pelvic or abdominal macroabscess	IIb	Diverticulitis with abscess
	Type 2c1	Free perforation with purulent peritonitis	III	Free perforation with purulent peritonitis	IIc	Free perforation
	Type 2c2	Free perforation with fecal peritonitis	IV	Free perforation with fecal peritonitis
Chronic diverticular disease	Type 3a	Chronic symptoms related to diverticulum after acute diverticulitis	–	–	–	–
	Type 3b	Recurrent diverticulitis	–	–	III	Chronic recurrent diverticulitis
	Type 3c	Identification of inflammatory stenoses, fistulas, conglomerate tumor	–	–
Diverticular bleeding	Type 4	Identification of source of bleeding	–	–	–	–