Gastrointestinal diseases (abbrev. GI diseases or GIillnesses) refer to diseases involving the gastrointestinal tract, namely the oesophagus, stomach, small intestine, large intestine and rectum, and the accessory organs of digestion, the liver, gallbladder, and pancreas. Gastrointestinal disorders include such conditions as constipation, irritable bowel syndrome, hemorrhoids, anal fissures, perianal abscesses, anal fistulas, perianal infections, diverticular diseases, colitis, colon polyps and cancer. Many of these can be prevented or minimized by maintaining a healthy lifestyle, practicing good bowel habits and submitting to cancer screening. Structural disorders are those in which the bowel looks abnormal and doesn't work properly. Sometimes, the structural abnormality needs to be removed surgically. Common examples of structural GI disorders include hemorrhoids, diverticular disease, colon polyps, colon cancer and inflammatory bowel disease.