Gastrointestinal diseases can cause symptoms like heartburn, constipation, diarrhea, and abdominal pain. Functional GI diseases affect how the digestive system works without visible organ... Here are 13 of the most common diseases of the digestive system, which range from constipation to gastrointestinal (GI) cancer. Thirteen common diseases of the digestive system include: Constipation: In the United States, approximately 63 million people have chronic constipation. Gastrointestinal diseases affect the gastrointestinal (GI) tract from the mouth to the anus. Examples include diarrhea and GERD. There are two types: functional and structural. Gastrointestinal diseases (abbrev. GI diseases or GI illnesses) refer to diseases involving the gastrointestinal tract, namely the esophagus, stomach, small intestine, large intestine and rectum; and the accessory organs of digestion, the liver, gallbladder, and pancreas.
