Gallstones

Gallstones: "Don't people need their gallbladder?
Fortunately, the gallbladder is an organ that people can live without. Losing it won't even require a change in diet. Once the gallbladder is removed, bile flows out of the liver through the hepatic ducts into the common bile duct and goes directly into the small intestine, instead of being stored in the gallbladder. However, because the bile isn't stored in the gallbladder, it flows into the small intestine more frequently, causing diarrhea in about 1 percent of people."
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I believe the percentage is MUCH higher than the oft quoted 1%
You should never take the removal of an organ lightly.