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What is Colorectal Cancer?

Colorectal cancer is cancer that starts in the colon or rectum. Most colorectal cancers start as a growth on the inner lining of the colon or rectum, called a polyp. If cancer forms in a polyp, it can grow into the wall of the colon or rectum over time.



Many lifestyle-related factors have been linked to colorectal cancer, such as:

  • Being overweight or obese
  • Physical inactivity
  • Certain types of diets (low-fiber, high-fat)
  • Smoking
  • Alcohol use

Other risk factors include age (over 45), personal history of colorectal polyps/cancer, personal history of inflammatory intestinal conditions, family history of colorectal cancer/adenomatous polyps, inherited genes/syndromes, racial and ethnic backgrounds, and type 2 diabetes.


Colorectal cancer might not cause symptoms right away, but if it does, it may cause one or more of these symptoms:

  • A change in bowel habits, such as diarrhea, constipation, or narrowing of the stool, that lasts for more than a few days
  • A feeling that you need to have a bowel movement that’s not relieved by having one
  • Rectal bleeding with bright red blood
  • Blood in the stool
  • Cramping or abdominal pain
  • Weakness and fatigue
  • Unintended weight loss

Because these symptoms may overlap with those of other conditions, it is important to get the correct diagnosis to find the right treatment. Make an appointment with your primary care physician if you are experiencing persistent signs and symptoms that concern you.


Screening can detect precancerous growths that can be removed, or detect cancer at an early stage when treatment is less extensive and more successful. The American Cancer Society recommends that people of average risk of colorectal cancer start regular screening at age 45. Average risk means you do not have a personal or family history of colorectal cancer or certain types of polyps, a personal history of inflammatory intestinal conditions, a confirmed or suspected hereditary colorectal cancer syndrome, or a personal history of radiation exposure to the abdomen or pelvic area. Average-risk individuals who are in good health with a life expectancy of more than 10 years should continue regular screening through the age of 75. If you are between ages 76 and 85, talk with your doctor about your preference, overall health, and prior screening history. Screening is not recommended after the age of 85.

There are two types of screenings: stool-based tests and visual (structural) exams. Stool-based tests are less invasive, but must be done more often, and are typically not recommended for high-risk individuals. Visual exams look at the structure of the colon and rectum for abnormal areas. This can be done with a scope inserted into the rectum, or special X-ray tests.

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"From my first visit, I was confident the team at Alliance Cancer Care was going to use leading protocols to treat my cancer. I felt safe, cared for, and listened to when I had questions. Being close to home was key for me and my family so they could be with me throughout each appointment and treatment, Alliance made this possible."
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