You may be surprised to learn that colorectal cancer is the third most common cancer (excluding skin cancers) diagnosed in both men and women in the United States, and is the third leading cause of cancer-related deaths.

When it comes to preventing or surviving cancer, including colorectal cancer, knowledge is a powerful tool. Yet many Americans are unaware of the basic facts about this typically silent killer.

Memorial Hermann Medical Group gastroenterologist Shaheer Siddiqui, MD, answers frequently asked questions and dispels commonly held misconceptions about colorectal cancer.

What is colorectal cancer?
Colorectal cancer starts in the colon or rectum and, depending on where it begins, can be referred to as colon cancer or rectal cancer. Most colorectal cancers start as a growth, called a polyp, on the inner lining of the colon or rectum. Some — but not all — polyps turn into cancer.

"While colorectal cancer can be life-threatening if not detected early, it is treatable, especially if caught early," says Dr. Siddiqui.

What causes colorectal cancer?
A number of factors can put you at higher risk of developing colon cancer, says Dr. Siddiqui. "Having an immediate family member who has had colon cancer puts you at greater risk, as does consuming a diet low in fiber and high in fats, red meat, calories, and sugar. Individuals who are obese — those with a body mass index (BMI) of 30 to 39.9 — and individuals with type 2 diabetes are also at greater risk. And certain segments of the population, including males, African Americans, and people ages 60 and older, are statistically more likely to be diagnosed with colorectal cancer."

And while the overall death rate from colorectal cancer has dropped — likely due to increased screening and improved cancer treatments — deaths from colorectal cancer among people younger than 55 are increasing.

What are the symptoms of colorectal cancer?
"The worst part about this type of cancer," says Dr. Siddiqui, "is that often there are no symptoms, at least with early-stage cancer. Patients often tell me, 'If I'm feeling fine, why would I think I have cancer?' And I tell them, you don't need to feel sick in order to have a malignancy. That's why cancer kills so many people."

As the disease slowly progresses, however, symptoms often appear, including bloody stool; frequent gas, abdominal pain, or cramping; a sense of incomplete bowel emptying; changing bowel movements or bowel habits; a constant feeling of weakness or exhaustion; and/or unexplained weight loss.

How is colorectal cancer diagnosed?
"A colonoscopy is one of the best ways we have to detect colon cancer," says Dr. Siddiqui. "It is an extremely important screening tool, given many people with colon cancer do not show symptoms in the early stages."

The American Cancer Society recommends beginning screenings at age 45* for people with average risk for colon cancer. If you have a family history of colon polyps or colon cancer, your doctor may recommend starting earlier.

"Many people put off a colonoscopy because they don't know what to expect," says Dr. Siddiqui. "If you talk to your doctor, you will understand that it is a very routine screening exam."

How can I prevent getting colon cancer?
While some risk factors may be out of your control, Dr. Siddiqui says you can reduce your risk of colorectal cancer by adopting a healthy lifestyle. Eat a diet rich in fruits, vegetables, and whole grains and light on red meat. Exercise regularly, don't smoke, and restrict your alcohol intake.

Can colon cancer be treated?
Depending on the stage of the disease and other factors unique to the patient, colorectal cancer treatment might include surgery, radiation, and/or chemotherapy. "At Memorial Hermann, our multidisciplinary team of specialists provides patients with the most advanced treatment based on their individual needs. We guide them through the process, supporting them every step of the way," he says.

Take action now
Check with your doctor to see if you should be screened for colorectal cancer. If you don't have a doctor, visit memorialhermann.org to find one. While there, you can also schedule and confirm your colonoscopy at a Memorial Hermann location that is convenient to you.

*Due to recent changes in screening recommendations, please consult your insurance provider to confirm coverage if you are under age 50.