Four-sample lactose hydrogen breath test for diagnosis of lactose malabsorption in irritable bowel syndrome patients with diarrhea

Table 2 H₂ peak and time to H₂ peak in three-dose lactose hydrogen breath test

		Lactose dose			P value
		10 g	20 g	40 g	10 g vs 20 g	20 g vs 40 g
IBS-D	H2 peak	38.5	57	92	0.010	0.000
	(ppm)	(27.3-47.3)	(32.0-85.0)	(58.0-127.0)
	Tp	153.5 ± 32.9	151.5 ± 35.9	151.3 ± 29.6	0.702	0.613
	(min)
HVs	H2 peak	38	66	99	0.004	0.001
	(ppm)	(29.5-46)	(36.5-90.5)	(56.5-135.5)
	Tp	152.1 ± 25.2	148.1 ± 30.7	139.3 ± 30.0	0.602	0.127
	(min)

IBS-D: Irritable bowel syndrome patients with diarrhea; HVs: Healthy volunteers; Tp: Time to H₂ peak.