Colon and Rectal Cancer

What To Know About Colon and Rectal Cancer

For some reason, the lower part of the digestive system, the colon and the rectum, are susceptible to cancer. Between 200,000 and 3 million people are said to contract colorectal cancer every year in the United States. The good news is that if these cancers are found early they can be very successfully treated. The most popular diagnostic tests, the colonoscopy or test for occult fecal blood, are minimally invasive or noninvasive.

Colon and Rectal Cancer

What Is Colon Cancer?

Like other cancers, colon and rectal cancers happen when the cells in the large intestine start growing out of control. They damage and destroy healthy cells in the area and can metastasize to other organs in the body and damage them. The cancers can occur anywhere in the large intestine. When they are found in last few inches of the organ, they are referred to as cancer of the rectum.

Undiagnosed colorectal cancer is especially dangerous because in the early stages the symptoms are often silent. Symptoms commonly start to appear after the disease is advanced and harder to treat. The symptoms include:

  • Blood in the stool or bleeding from the rectum
  • A change in bowel habits. The person might suffer from alternating diarrhea and constipation.
  • Abdominal cramps that won’t go away
  • Weight loss that can’t be explained
  • Fatigue

Save rectal bleeding or blood in the stool, the symptoms are so nonspecific that people can be tempted to ignore them. They are, for example, the same symptoms as the harmless but annoying irritable bowel syndrome.


Because symptoms of colorectal cancer can be vague, medical professionals recommend that people over 50 be screened regularly, especially if there is a family history of the disease. A doctor uses a colonoscope, a tool with a flexible tube attached to a tiny camera attached to a video monitor, to check the large bowel. If he finds anything that looks suspicious, he can remove it right away and have it biopsied. A sigmoidoscope is a device that checks the lower part of the bowel. If the patient can’t tolerate a scope, a CT scan can also be used.


If cancer is found, it will be staged depending on whether or not it is still contained within the intestine or has spread, either to local lymph nodes or more distant sites. In its earliest stages, the cancer can be resected with no need for further treatment. If the cancer’s more advanced, surgery may be used with radiation, chemotherapy or targeted drugs.