Is soy formula recommended in acute diarrhea due to gastroenteritis? Why?

• A. Yes, because soy reduces lactose intolerance
• B. Yes, because it prevents lactase deficiency
• C. No, because gastroenteritis can cause secondary lactase deficiency; lactose-free formula would be beneficial
• D. No, because soy increases galactose

Answer: (D)

During acute gastroenteritis, the intestinal lining can have reduced lactase activity, leading to transient lactose malabsorption. Introducing lactose-containing feeds can worsen stool output and dehydration, so lactose-free options are preferred for short-term management. Soy formula is not recommended in this setting because it can increase exposure to galactose, and a higher galactose load in the gut may worsen diarrhea or tolerance when the mucosa is inflamed. Therefore, avoiding soy in acute diarrhea due to gastroenteritis is advised. This contrasts with lactose-free formulas (or continuing breastfeeding with careful rehydration), which address the lactase deficiency component rather than adding extra galactose.