What Is the Relationship between Constipation and Colon Cancer?

Both men and women are at risk of developing colon cancer, a disease that causes malignant tumors to grow in the colon, or large intestine. The relationship between constipation and colon cancer is that constipation is a symptom of colon cancer. It is important to note, however, that several symptoms of this cancer are commonplace and may indicate less serious conditions. Constipation and colon cancer, for example, do not always occur together. If a patient experiences constipation along with other symptoms of colon cancer, though, further testing should be done.

Constipation is characterized by infrequent defecation. It is not necessary to have a bowel movement every day, but a frequency of less than three per week is considered constipation. Patients may experience difficulty moving their bowels due to a lack of fiber or liquids in their diets, holding back bowel movements or disruptions in their daily routines. Constipation and colon cancer may be linked if the patient's gastrointestinal tract is narrowed or blocked by polyps, which are abnormal growths that can be malignant.

Additional symptoms, other than constipation, typically need to be present to indicate cancer. These symptoms include weight loss; fatigue; and bleeding from the rectum, either with or without visible blood in the stool. Patients with colon cancer may also feel as though they still need to go to the bathroom even after having a bowel movement.

In other cases, the patient's age, genetics or existing medical conditions may make it more likely that constipation is a sign of colon cancer. Most colon cancer cases occur in people over the age of 50. People with family histories of colon cancer as well as those of African American or Ashkenazi Jewish descent also are more prone to the condition. Medical conditions such as obesity or type 2 diabetes are risk factors as well.

Early detection is vital in treating colon cancer. Anyone who experiences prolonged, unexplained constipation or infrequent defecation along with other symptoms of the disease should consult a doctor as soon as possible. Tests such as colonoscopies, fecal occult blood tests and double contrast barium enemas can diagnose colon cancer quickly so that treatment can begin. Patients should also undergo a series of screening tests — the frequency of each test and the age at which testing should begin is generally determined by the risk group into which the patient falls. Those that fall into the high-risk category may need to begin some tests as early as age 10, while patients at average risk can typically postpone testing until they are 50.