Colon cancer is cancer of the colon or rectum. It is one of the most common forms of cancer, with more than 146,000 new cases diagnosed in 2009, according to the American Cancer Society. It is the third-leading cause of cancer-related deaths in the United States. Gas is only one of many possible symptoms of colon cancer. In many cases, people with colon cancer experience no early signs of the disease, according to the Mayo Clinic.
People with colon cancer may frequently experience bouts of severe gas or abdominal bloating or fullness, according to the National Institutes of Health. However, gas and bloating are common signs other medical conditions, including many gastrointestinal conditions. Other gastrointestinal symptoms of colon cancer include nausea and vomiting.
Colon cancer often causes noticeable changes in bowel habits. For example, both diarrhea and constipation can develop, and the consistency of the stool may be noticeable different for an extended period of time. Some people also feel as though their bowels are not emptying or notice that the stool is more narrow than usual.
Another possible sign of colon cancer is blood in the stool, according to the National Cancer Institute. The blood can be either bright red or dark, depending on when it entered into the stool.
Colon cancer can lead to unexplained weight loss. However, colon cancer is a common symptom of many other medical conditions, including many other forms of cancer.
Fatigue and body weakness are also signs of colon cancer, according to the National Cancer Institute. However, fatigue is another general sign of many types of cancer and is also a common symptom of other medical conditions. Other general signs of cancer include fever, pain and skin changes such as jaundice and pigment changes, according to the American Cancer Society.