Table 1.

Distribution of opacity, homogeneity and location of sand accumulations (parameters from Keppie et al.) in sand colic cases and controls

		Controls (n = 20)		Sand colic (n = 37)		Chisq
Variable	Categories	Number	Percent	Number	Percent	p-value
Opacity	Equally dense	8	40	3	8	0.004
	More dense	12	60	34	92
Homogeneity	Homogenous	8	40	30	81	0.002
	Mixture	12	60	7	19
Location	Cranioventral	25	89	34	92	0.418
	Other	3	11	3	8