Excess coffee and caffeine affect the body. The Coffee Research Institute reports more than half of Americans drink coffee on a daily basis. Twenty-five percent drink coffee occasionally. Coffee can be habit forming, leading to excessive consumption. Due to its acidic nature and caffeine content, excessive consumption may have negative effects on the stomach.
One possible health effect of excess coffee and caffeine consumption on the stomach is gastroesophageal reflux disease, or GERD. This condition may increase gastric ulcers and increase the risk for gastric cancer, according to an article in the 2006 "Methods and Findings in Experimental and Clinical Pharmacology" journal. Researchers are looking into ways to cut down the acid content in coffee, which will help GERD patients.
The stimulant effects of caffeine in coffee may occur in several areas of your body, including your gastrointestinal tract. Caffeine directly stimulates the nerves that control intestinal activity, according to the University of North Carolina Center for Functional GI and Motility Disorders. The increase in intestinal activity means coffee may have a laxative effect. For some, it speeds up the intestine so much that it causes diarrhea. Diarrhea may lead to dehydration and loss of nutrients in the gut that otherwise would have been absorbed.
Nausea and Stomachache
Excess coffee consumption may cause the stomach to ache and may give you an overall nauseous feeling. This effect doesn't occur for everyone, but for some it may be quite painful. This nausea and ache may occur from over-stimulation of the nerves in the stomach, dehydration and over-production of acid.