Bag has the following meanings in the field of medicine:

1. A sac, pouch, or container. A good example is a colostomy bag
(see picture to the right), which is an external pouch used to
contain feces (poop) after a section of the colon has been
removed. The colon is the major part of the large intestine, which
is located in the belly. The intestine is a tube shaped structure
that is part of the digestive tract.

Another common example is a body bag (also known as a
cadaver pouch), which is used to temporarily store dead bodies
when removed from the scene of death and taken to a morgue.
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2. A body part or organ that is like a pouch or that is hanging downward and/or swinging
freely. The urinary bladder is sometimes described as a bag-like structure in which urine
is stored.

3. A flexible or expandable sac or ouch that is designed to hold fluid, gas, or part solid
material. A good example is a bag of crushed ice applied to the body to treat a sprain.

Several types of bags are used in medical or surgical procedures to widen body
openings. Bag comes from the Old Norse word “baggi” meaning “pack or satchel.”
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A colostomy bag.