Colon Cancer FAQs


A gastroenterologist is a physician who specializes in the diagnosis and treatment of disorders of the gastrointestinal tract, including the esophagus, stomach, small and large intestines, pancreas, liver, gallbladder and biliary system. A gastroenterologist must first complete an internship and a three-year internal medicine residency and is then eligible for additional specialized training in gastroenterology. This fellowship is also three years long, so by the time gastroenterologists have completed training, they have had six years of additional specialized education following medical school.

Colon cancer forms in the tissues of the colon, which is the largest part of the intestine. Most colon cancers begin in cells that make and release mucus and other fluids to aid in digestion and the elimination of waste products.

Although scientists are unsure of the exact causes of colon and colorectal cancer, some risk factors have been identified, including:
  • Being age 45 or older
  • Living a sedentary lifestyle
  • Eating a high-fat diet
  • Smoking
  • Drinking alcohol
  • Having had radiation therapy for cancer
  • Having diabetes, obesity, or growth hormone disorder
  • Having family or personal history of colon polyps, colon cancer, ulcerative colitis, Crohn’s Disease or other inflammatory bowel disease

Many cases of colon cancer have no symptoms or warning signs until the cancer has advanced; however, the following symptoms may indicate colon cancer:
  • Changes in bowel habits
  • Blood (either bright red or very dark) in the stool
  • Abdominal pain
  • Unexplained weight loss
  • Bloating, fullness or cramps
  • Vomiting
Most often, these symptoms are not due to cancer. Other health problems can cause the same symptoms. Anyone with these symptoms should see a doctor to be diagnosed and treated as early as possible.

Research has shown that people with certain risk factors are more likely than others to develop colon cancer. A risk factor is something that may increase the chance of developing a disease.

Studies have found the following risk factors for colorectal cancer:
  • Age
  • Family history
  • Inflammatory bowel disease (IBD)
  • Smoking
  • A high-fat diet
  • A sedentary lifestyle
  • Obesity
  • Diabetes
  • Alcohol
Because people who have had colon cancer once may develop it a second time, it is important to have checkups. Also, if a patient is diagnosed, they may be concerned that family members may develop the disease. People who think they may be at risk should talk with their healthcare provider. The provider may be able to suggest ways to reduce the risk and can plan an appropriate schedule for checkups.

Keep in mind that while risk factors can increase an individual’s possibility of getting colon cancer, about 75 percent of those who are diagnosed with it have no family history and no apparent symptoms.

In the United States, colorectal cancer is the third most common cancer in men, after prostate and lung cancer. It is also the third most common cancer in women, after breast and lung cancer.

Getting screened is the first step in preventing colon cancer. Screening should begin at age 45 for people without any risk factors for developing colon cancer. Recent studies suggest that African Americans may want to start screening before age 45. There are also certain lifestyle changes that can be made to prevent colon cancer, such as leading an active lifestyle and eating a diet high in fiber and fruits and vegetables.

Several colon cancer screening options are available, including colonoscopy and flexible sigmoidoscopy. More frequent and earlier screening is recommended if you are at a high risk for colon cancer. Remember that these procedures not only detect cancer; they also prevent it by removing any tissue that could potentially become cancer during the same procedure.