Caffeine can trigger the symptoms of irritable bowel syndrome (IBS) -- especially abdominal cramping and diarrhea -- as well as aggravate heartburn and dyspepsia. It does so by stimulating the gut directly; by stimulating the brain and heart, which contributes to anxiety; and by interfering with sleep. Many people do not realize that caffeine can cause or contribute to IBS, fibromyalgia, headache, jittery feelings, sleep disturbance, fatigue, malaise, irregular heartbeat, panic and anxiety attacks.
