Lactose intolerance isn’t an allergy. The body just lacks lactase in the small intestine for breaking down the lactose. Which means the lactose goes off into the colon unprocessed, where bacteria will gladly ferment it, which causes tons of gas to be released, which is what causes bloating and pain.
Additionally, to quote Wikipedia:
The unabsorbed sugars and fermentation products also raise the osmotic pressure of the colon, causing an increased flow of water into the bowels (diarrhea).
And really, lactose intolerance during adulthood is kind of the default. It’s only mostly just humans in Europe that started evolving towards adult lactose tolerance.
Lactose intolerance isn’t an allergy. The body just lacks lactase in the small intestine for breaking down the lactose. Which means the lactose goes off into the colon unprocessed, where bacteria will gladly ferment it, which causes tons of gas to be released, which is what causes bloating and pain.
Additionally, to quote Wikipedia:
https://en.wikipedia.org/wiki/Lactose_intolerance#Causes
And really, lactose intolerance during adulthood is kind of the default. It’s
onlymostly just humans in Europe that started evolving towards adult lactose tolerance.