Persistent abdominal pain, sometimes associated with gas or cramps, may occur in patients with colon cancer, states Mayo Clinic. In the early stages of the disease, there are often no symptoms. When symptoms occur, they vary depending on the size of the cancer and its location within the large intestine.
A change in bowel habits, such as diarrhea, constipation and narrowing of the stool, is a possible symptom of colon cancer, states the American Cancer Society. Rectal bleeding and blood in the stool may also occur. After a bowel movement, an individual may feel as though he still needs to relieve himself. Weakness, fatigue and loss of weight are other possible indications that colon cancer is present.
Because colon cancer often causes no symptoms in the early stages when it is most treatable, screening is recommended, notes the American Cancer Society. Most people begin periodic screening for colon cancer at the age of 50, but those at higher risk of developing the disease often start sooner, according to Mayo Clinic, African Americans, Native Americans and those with a family history of colon cancer need to begin early screening. Eating a balanced diet that includes fiber and antioxidants can help prevent colon cancer, as can engaging in regular exercise, avoiding alcohol and quitting smoking.