Discomfort or pain in the stomach caused by difficulty in digesting food; dyspepsia.
From in- (not) + digestion (from Latin 'digerere' meaning to carry apart). It literally means the failure of food to be properly 'carried apart' in the stomach.
Your stomach produces a new layer of mucus every three to five days—without this protection, stomach acid would digest the stomach itself, which is exactly what happens in ulcers when this defense breaks down.
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