Rectal Cancer Symptoms

Warning Signs to Look out For

Rectal Cancer Symptoms
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Rectal cancer is a type of cancer that develops in the rectum, the bottom portion of the colon (or large intestine) that's closest to the anus. Like other organs in the body, the rectum is vulnerable to many diseases and conditions, including cancer.

In the early stages, a patient who has rectal cancer may not have symptoms. With advanced disease, more symptoms may appear. Every patient, of course, is different.

Check out the list of possible symptoms of rectal cancer, below, and remember that all of these symptoms can be seen with other more common and less serious conditions.

Rectal Cancer Symptoms

  • Blood in the Stool: Rectal bleeding (either bright red or dark red in color) is a common symptom of rectal cancer. It may not always be apparent, though. A test called a fecal occult blood test (FOBT) detects blood in the stool that cannot be seen. Keep in mind, though, that rectal bleeding is also associated with less severe health problems, such as hemorrhoids and anal fissures. Also remember that some foods, like beets, watermelon, and red licorice can cause changes in stool color. To be on the safe side, always report any changes in stool color to your doctor.
  • Thin Stools: A change in the pattern of a bowel movement to thin- or ribbon-like stools may indicate a problem. A growth in the colon or rectum that is partially obstructing the bowel can change the size and shape of the stool as it exits the body. Other conditions may also cause thin stools, like a large benign polyp or hemorrhoids. How thin is too thin? A thin stool is considered to be as thin as a pencil. If you consistently notice thinner stools, and this is a change for you (even if they aren't as thin as a pencil), let your doctor know.
  • A sensation of Rectal Pressure or Fullness: If you feel like you have to empty your bowel, even after just doing so, or if you feel that you are repeatedly not emptying your bowel fully, talk to your doctor. A mass in your rectum can give you that sensation.
  • Fatigue: Fatigue that lasts more than a few days can indicate a medical problem. Fatigue that's related to rectal cancer can be due to anemia, because of blood loss in the stool. Like other symptoms of rectal cancer, fatigue is a vague symptom and can be related to many other less serious conditions. 
  • Diarrhea or constipationVery loose or very hard stools can sometimes be a symptom of rectal cancer, though these symptoms can be related to many other causes, such as diet or Irritable Bowel Syndrome. 
  • Abdominal discomfort: If you're regularly feeling bloated, or you're experiencing lots of cramps or gas pains, tell your doctor. 
  • Unexplained weight loss: If you're losing pounds but you're not eating less or exercising more, and you can't figure out why you're getting thinner, alert your physician.


Overview: Colon and Rectum Cancer: What Causes Colorectal Cancer? American Cancer Society. 15 Mar. 2006. 14 July 2009.