Primarily malabsorptive due to infection of mature absorptive villous enterocytes of small intestine, but toxin-mediated secretory component also contributes [1]. The NSP4 non-structural glycoprotein may contribute to the development of diarrhea via non-competitive inhibition of the Na+-D-Glucose symporter, preventing water reabsorption even in the absence of histological damage to the villi [44]. This evidence concerns the gene PRSS57 and infection.