Your colon, also known as the large intestine, is part of your digestive system. It's a long, hollow tube at the end of your digestive tract where your body makes and stores stool. Many disorders affect the colon's ability to work properly. Some of these include
Colorectal cancer
Colonic polyps - extra tissue growing in the colon that can become cancerous
Ulcerative colitis - ulcers of the colon and rectum
Diverticulitis - inflammation or infection of pouches in the colon
Irritable bowel syndrome - an uncomfortable condition causing abdominal cramping and other symptoms
Treatment for colonic diseases varies greatly depending on the disease and its severity. Treatment may involve diet, medicines and in some cases, surgery.
NIH: National Institute of Diabetes and Digestive and Kidney Diseases