Clinical features

Ask about speed of onset ^c

Why?

An insidious onset makes inflammatory bowel disease more likely, and an acute one less

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability
colitis undergoing sigmoidoscopy c (pre-test probability: 50%)	inflammatory bowel disease (stool culture, histology, follow-up)	insidious onset	18 (2.6 to 120)	95%
		acute deterioration, previous slight symptoms	5.5 (0.74 to 42)	84%
		subacute onset	1.5 (0.53 to 4.5)	58%
		acute onset	0.095 (0.036 to 0.25)	9%