Poop-o-meter
MAYBE.
Consulting the colon…
Does decaf coffee make you poop?
Sometimes, but weaker than regular. Decaf has almost no caffeine, yet some people still have to run after a cup. It's a smaller push than regular coffee, and in one study it barely beat water.
Strength Mild
Kicks in within minutes
Main culprit coffee itself
Did decaf coffee make you go?
The meter says what should happen. Your bowels get a vote too.
Why it works
Caffeine isn't the only trigger
In a 1990 survey of people who said coffee made them go, decaf set off the urge too, so something in coffee besides caffeine plays a part.
But it's the weaker cup
In gut-pressure tests, decaf moved the colon less than regular coffee, and not by enough to clearly beat plain water.
Almost no caffeine
An 8 fl oz cup of decaf has about 2 mg of caffeine, against roughly 96 mg in regular coffee.
Sources: Brown, Cann & Read, Gut 1990; Rao et al., Eur J Gastroenterol Hepatol 1998; USDA FoodData Central.