eli5: where does stomach acid go when digested food moves to your intestines?

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eli5: where does stomach acid go when digested food moves to your intestines?

In: Biology

In the first part of your small intestine, the [duodenum](https://en.wikipedia.org/wiki/Duodenum), the acidity gets reduced because your pancreas dumps in a bunch of bicarbonate ions, which are basic.

It goes into a section of your stomach that is extremely alkaline which balances out the acid.

It’s neutralized by bicarbonate (baking soda, basically), which is released by the pancreas into the first part of the intestine, directly after the stomach. Hydrochloric acid plus bicarbonate produces salt and CO2. The salt needs no further care, and the CO2 is absorbed into the blood and leaves through the lungs.

The same hormone (secretin) that makes the pancreas release bicarbonate also releases gall from the gall bladder. (Gall made by the liver, but collected in the gall bladder until needed). Gall is more complicated – it is alkaline, and helps with neutralising the stomach acid, but that’s not the main purpose of it: Gall works sort of like a soap, and helps fats and oils stay mixed into water as tiny droplets instead of sticking together in large blobs. Apparently this makes them much easier to absorb and make use of. It also destroys some kinds of bacteria and viruses, in case they survived the stomach acid.