QUESTION: Digestion, how long does it take? How long does it take to digest food — from the time you eat it to the time you excrete it in stool?
ANSWER from Michael F. Picco, M.D: Digestion time varies depending on the individual. For most healthy adults, it’s usually between 24 and 72 hours. After you eat, it takes about six to eight hours for food to pass through your stomach and small intestine. Food then enters your large intestine (colon) for further digestion and absorption of water. Elimination of undigested food residue through the large intestine usually begins after a total of 24 hours. Complete elimination from the body may take several days. More if you’ve eaten a large quantity, or eaten heavy foods. You digest much more slowly with an overloaded system. Water is crucial to keep everything in motion.
Andrea: That’s good to know. Four days ago I’d over-eaten some Tyson buffalo chicken bites and gave myself indigestion. I felt kind of stuffed for a few days afterward, so I only ate clear soups for 3 days. Even so, I was surprised to find myself eliminating much more than I thought I would while I was eating no solid food. I’m health conscious. I pay attention to what goes in my body and what comes out of my body. It made sense that the bowel movements I was having on Tuesday and Wednesday were from the meals I’d eaten Saturday and Sunday. Good to know.
I also stopped drinking water for a few days, so my digestive system slowed to a crawl. I just wasn’t thirsty. I felt fine and didn’t realize I was dehydrated. Eating processed food and being dehydrated is a recipe for constipation, which I’d never had before. My digestive system felt heavy and weighed down. A nurse friend suggested a tried and true fix: Mix 2 oz of milk of magnesia into 4 ounces of warmed prune juice. Nurses call this “a black and white.” Follow with 8 oz warm water (essential to success). Expect a bowel movement within 30 minutes to 6 hours. Milk of Magnesia is a saline laxative which means it acts by drawing water into the intestine to help gently pass the bowel movement. Keep sipping water to hydrate.
Knowing how long it takes for food to move through my body helps me make more informed eating choices. And discovering how crucial water is to keep everything flowing makes me more mindful to stay hydrated.