Colon cancer symptoms vary according to the stage of the cancer.
Colon cancer symptoms vary according to the stage of the cancer. The Mayo Clinic reports that symptoms also vary according to the location of the cancer and the size of the tumor. It is not uncommon for people to report no symptoms associated with early stage colon cancer; however, as colon cancer progresses, the likelihood of symptoms increases. Common symptoms of colon cancer include a change in stool composition, a change in bowel habits, abdominal pain, cramping, gas, blood in the stool, fatigue and weight loss. While many people experience these symptoms from time to time, persistent symptoms may indicate something more serious, such as colon cancer.
Changes in bowel habits associated with colon cancer vary. Some patients experience diarrhea, while other patients suffer from periods of constipation. Generally, these changes in bowel habits persist for more than a few days. Colon cancer may also cause the stool to look different. If there is old blood in the stool, then it may appear black. In addition, if the tumor is large enough, it may partially or completely obstruct the passageway through the intestine. When this happens, the size of the stool may change, appearing smaller and narrower than usual. Sometimes the stool is so narrow it appears as thin as a pencil.
Some colon cancer patients experience abdominal discomfort in the form of pain, cramping or gas. Sometimes the abdominal pain accompanies bowel movements. Occasionally, patients note that they feel as though their bowel has not completely emptied after a bowel movement. In addition, colon cancer patients may feel nauseous and experience vomiting.
The American Cancer Society notes that colon cancer patients often experience rectal bleeding or blood in the stool. The blood may appear bright red, suggesting that it is fresh, or older blood will be colored black. Even though bright red blood on the tissue is more commonly indicative of hemorrhoids or anal fissures, blood on the tissue or stool should always be evaluated by a physician. If bleeding is severe, the patient may present as anemic on a blood test.
The University of Maryland Medical Center classifies symptoms of colon cancer according to the location of the cancer in the colon. If the cancer is in the cecum and ascending colon, otherwise known as the right colon, then the patient is likely to experience symptoms, such as bleeding, weakness, tiredness, shortness of breath and a palpating heart.
Cancers of the upper colon, otherwise known as the transverse colon, include bleeding, cramping, gas and anemia. In addition, colon cancer of the transverse colon may lead to intestinal obstruction or bowel perforation.
Cancers of the descending colon and rectum, also known as the left colon, may produce symptoms, such as narrow stools, pain, a feeling of fullness or bloating, painful bowel movements, frequent urge to have a bowel movement, which is not relieved after a bowel movement, and bright red bleeding.