The colon or the large intestine extends from the cecum to the rectum. Colon's main function is to extract water from feces. Colon, also called large bowel, measures 1.5 meters in length. There are various diseases of the colons like colitis, colon cancer, constipation, polyposis, pseudomembranous colitis, ulcerative colitis, diverticulosis, diarrhea, and chronic functional abdominal pain.

The colon consists of various parts. The cecum is found in mammals, birds, and certain reptiles. The appendix is a part of the cecum. The ascending colon is from the cecum to the hepatic flexure and is present on the right side of the abdomen. The transverse mobile colon is attached to the stomach with the help of a wide band of tissue called mesocolon. A descending colon is the part between the splenic flexure to the beginning of the sigmoid colon. The sigmoid colon is between the descending colon and the rectum. The rectum is the last part of the colon.

The colon cancer is the third most common form of cancer and the second most deadly one in the western world. Change in bowel movements like constipation or diarrhea, lower abdominal chronic pain, and blood mixed in feces are some of the early symptoms. Sometimes, without giving any symptoms, the tumor can enlarge and perforate the intestine or block it. Sigmoidoscopy or colonoscopy is carried out to detect the presence of colon cancer. A camera or a flexible fiber-optic camera is inserted into the body through the anus to inspect the colon.

Colon cancer can occur due to hereditary reason. Improper diet, consuming loads of meat, fatty food, and lack of fiber, fruit and vegetables in the diet can all cause colon cancer. It is usually the people of the western world who are prone to colon cancer due to their nutrition-less diet. Even chain smokers and drinkers are prone to colon cancer.

There are various ways of reducing the risk against colon cancer. Some of them include eating fresh fruits and vegetables, consuming calcium rich products, and daily exercise. Aspirin is said to reduce the growth of colon polyps and cancers of the colon, stomach, and esophagus. But it may also cause bleeding of the intestine, and ulcer. The symptoms are usually avoided by the people, but it is important to consult the doctor immediately when such symptoms occur, since the survival rates for early detection of colon cancer is five times more than that of late stage cancer.