The human stomach renews its entire lining every few days.
Why it is true
Gastric acids are so strong they would corrode the organ itself if it weren't for rapid cell regeneration. The cells of the stomach lining completely replace themselves in a cycle of three to four days.
Source: Scientific American
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Related facts
The human stomach replaces its lining every three to four days.
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The human stomach produces a new lining every three to four days.
It takes your body roughly 12 to 24 hours to completely digest a meal.