More than 125,000 new cases of colon cancer occur annually in the U.S., making it one of the most frequent cancer diagnoses, according to the American Society of Colon and Rectal Surgeons. Most colon cancers develop from a polyp in the lining of the colon, according to the National Comprehensive Cancer Network. Depending on the site of the cancer in the colon, a tumor may grow several years before detection, which is why routine screening is important.
Changes in Bowel Habits
Changes in bowel habits are the most common symptoms in both early and advanced colon cancer, according to the National Cancer Institute. Constipation with less than three bowel movements a week, diarrhea with loose bowel movements three times a day lasting more than three days, or constipation alternating with diarrhea are common advanced colon cancer symptoms. Diarrhea may also lead to dehydration when too much fluid is lost in the body. Pain and discomfort may accompany both constipation and diarrhea. If bowel habits do not become regular after over-the-counter treatments, increased fluids and increased fiber, contact the doctor.
Bowel Obstruction
According to the National Cancer Institute, colon cancer is a common cause of bowel obstruction that occurs when the tumor grows large enough to block the passage of waste materials. Motility, or the ability of the colon to push wastes out, may be limited if the tumor grows large enough to interfere with nerves. Not having a bowel movement or having very small bowel movements for a period of weeks, pain in the lower part of the abdomen, a swollen or distended abdomen, and vomiting may all indicate a bowel obstruction according to the National Cancer Institute. Pencil sized or ribbon like bowel movements may develop when the growing tumor mechanically blocks the colon and reshapes the stool. Bowel obstructions may be life threatening if not treated promptly.
Bleeding and Anemia
Colon cancer can cause bleeding that is bright or dark red, according to the National Comprehensive Cancer Network. Bright red blood indicates current bleeding and dark red is usually seen with old blood that has been in the colon for a while. Blood in the stools should be reported to the doctor immediately. Bleeding may start slowly and increase over time leading to anemia, or low blood. When anemia develops, the blood can not carry enough oxygen for the body and shortness of breath may occur.
Pain and Discomfort
Swelling or bloating in the abdomen causes a feeling of fullness and clothes may get tight. Cramping or excess gas may also cause abdominal discomfort. Pains may be sharp or dull, but progressively get worse as the tumor grows. Early stage colon cancer does not usually cause pain. When pain is present, colon cancer is often at a later stage, according to the National Cancer Institute.
Issues with Food
Weight loss, nausea and vomiting occur with advanced colon cancer, according to the National Comprehensive Cancer Network. As the tumor grows, vomiting may occur because food can not move through the colon. Weight loss happens when nutrients in the food can not be absorbed or discomfort limits the ability to eat.
Metastases
Late stage colon cancers, Stage III and Stage IV, spread or metastasize through the lymphatic system to both nearby and far parts of the body. Stage III colon cancer has spread to lymph nodes and Stage IV colon cancer usually spreads to the liver, lungs and other organs, according to the National Cancer Institute. With liver metastases, the skin turns yellow or jaundiced. When colon cancer spreads to the lungs, difficulty breathing occurs. Other symptoms may develop depending on where the colon cancer cells travel in the body.
