Sugar alcohols are also called polyols. They are a kind of
(non-intoxicating) alcohols derived from sugar.  They taste sweet, but
many of them are very poorly absorbed and metabolized, making them very
low in dietary calories ... and sometimes causing them to act as strong
laxatives (because they pass right through the digestive tract, carrying
lots of water).

Sugar alcohols are used as low-calorie sweeteners in small amounts.  In
large amounts, they are used to purge the gastrointestinal tract of all
its contents before intestinal surgery or diagnostic procedures.  Eating
too much sugar alcohols in food may cause diarrhea, depending on which
one is involved.

Sugar alcohols include mannitol (often used to purge the GI tract),
sorbitol, xylitol (similar to sugar in sweetness and calories), isomalt,
erythritol (tastes like sugar, but has virtually no calories and does
not cause diarrhea), and many others.