It’s no secret that caffeine stimulates the brain. But for many, that morning cup of Joe also wakes up the other end of the body, prompting a timely bowel movement.
According to the American Chemical Society, coffee appears to have this laxative effect on about one-third of the population. What’s not clear is why.
Some would conclude that magical ingredient in coffee is caffeine. However, caffeinated sodas, energy drinks and chocolate bars don’t have the same effect. And, the laxative effect seems to occur regardless of whether the coffee is caffeinated or decaf.
Research indicates that some ingredient in coffee triggers the release of two hormones that aid in digestion, speeding up bowel movements. The hormone gastrin stimulates contractions of the stomach and intestinal tract, and cholecystokinin hormone triggers the release of digestive enzymes and bile that encourage the elimination process.
Another thought is that the acidic nature of coffee causes the stomach to secrete more gastric acid than usual. This can cause the stomach to dump its contents more quickly into the intestines, speeding up the digestive process.
Some argue that a morning bowel movement is merely the natural result of the gastrointestinal tract waking up after being inactive all night; that movement would occur when any food or drink enters the body. Still, the urge to eliminate after drinking coffee is 60 percent stronger than the effect induced by drinking water.
Via Christi doctor's take
Saritha Gorantla, MD, a gastroenterologist at Ascension Medical Group Via Christi on Murdock, believes it’s a combination of food entering the stomach combined with a relaxing morning routine that causes the movement.
“The important thing, she says, “is to have a solid bowel movement three or more times per week. And, if a relaxing morning cup of coffee works for you, enjoy!”