Coffee can make you poop because it quickly stimulates movement in the colon, which helps push stool toward the rectum. This effect may begin within minutes and can happen with both regular and decaffeinated coffee, so caffeine is not the only factor involved.
Coffee may also increase the release of digestive hormones, including gastrin, that encourage the stomach and intestines to become more active. Drinking coffee can trigger the gastrocolic reflex, a normal response in which the colon starts moving after something enters the stomach.
The urge may feel stronger in the morning because the colon is naturally more active at that time. Not everyone responds to coffee in the same way, and the effect may vary depending on the type, strength, temperature, and amount consumed.
An occasional bowel movement after coffee is usually not concerning. However, consider reducing the amount or switching to decaf if it regularly causes urgency, diarrhea, or discomfort. Persistent changes in bowel habits, blood in the stool, severe pain, or unexplained weight loss should be evaluated by a gastroenterologist.