Table 2: Sensitivity, specificity, PPV, and NPV of major symptoms after lactose intake

Symptoms		Sensitivity		Specificity		PPV		NPV		PLR		NLR
Diarrhea		58.45%		62.5%		90.22%		20.27%		1.56		0.66
Borborygmi		57.04%		58.33%		89.01%		18.66%		1.37		0.74
Flatulence		19.01%		79.16%		84.38%		14.18%		0.91		1.03
Abdominal pain		24.3%		70.83%		83.3%		13.70%		0.83		1.07
Nausea		3.5%		95.83%		83.33%		14.38%		0.84		1.00

PPV: Positive predictive value; NPV: Negative predictive value; PLR: Positive likelihood ratio; NLR: Negative likelihood ratio