A colon with what appears to be a tumor

Colon Cancer

The term colon cancer is sometimes used interchangeably with colorectal cancer because colon and rectal cancers share common features. The rectum and colon make up the large intestine. Colorectal cancer is the fourth most common cancer in the United States, and it’s the second leading cause of cancer-related deaths.

Most colon cancers are caused by growths within the inner lining of the colon, called polyps. The chance of a polyp developing into cancer depends on factors, like the type of polyp (adenomatous polyps are considered precancerous) or if it has abnormal cells (called dysplasia).

Through routine screenings, most polyps can be found and removed before they turn into cancer. Screening tests include visual tests (colonoscopy) and at-home stool tests (fecal immunochemical test).

Frequently Asked Questions

  • What causes colon cancer?

    Most colon cancer develops from polyps with abnormal cells that start growing uncontrollably. There are several risk factors that increase a person's chance of developing colon cancer, such as leading a sedentary lifestyle, smoking, heavy alcohol intake, having a family history of colon cancer, or having an inflammatory bowel disease (IBD).

  • How do you prevent colon cancer?

    The most important step is to talk to your doctor about colon cancer screenings. Those considered average risk are encouraged to begin screenings at age 45.1 Lifestyle factors that may also be helpful include moderating your meat consumption, eating more produce and fiber, getting moderate to vigorous exercise, avoiding smoking, and limiting alcohol consumption.

  • What are the symptoms of colon cancer?

    Symptoms may not occur initially, but as the disease progresses, a person may notice a change in their bowel habits (persistent diarrhea or constipation) or dark or bright red blood in their stools. Other symptoms may include abdominal pain, cramping, weight loss, loss of appetite, or fatigue.

Key Terms
Stomach pains
What You Should Know About Cecum Cancer
Caucasian doctor and patient using digital tablet at home
Carcinoid Tumors of the Colon and Rectum
Man throwing up in toilet with glass of water in foreground
Signet Ring Cell Adenocarcinoma Symptoms and Types
An illustration of a colon polyp
Overview and Types of Colon Polyps
Inside of a colon
What Is Function of the Colon?
a knit depiction of internal organs on a sweater
Malignant Bowel Obstruction in End Stage Colon Cancer
Colon Cancer: Overview and More
The inside of a vein showing white blood cells
The Role of Neutrophils in Cancer Treatment
Basophils and Their Role in Your Body
Elderly p. consulting, dialogue
Mucinous Adenocarcinoma of the Colon and Rectum
Conceptual image of a platelet.
Understanding Mean Platelet Volume (MPV)
Eosinophil; white blood cell (leukocyte), 400X at 35mm. Human blood smear. Eosinophils have a bilobed nucleus, and large, reddish cytoplasmic granules. Increased numbers of eosinophils (eosinophilia) occur in allergies. 1-3% of the total # of white
The Role Eosinophils Play in Cancer
Man lying in hospital bed
Leiomyosarcoma: Overview and More
Young Girl Receiving Chemotherapy Treatment
Colorectal Cancer in Children
Large intestine
Colon (Large Intestine): Anatomy, Function, Structure
Doctor speaking with patient
Macrophages and the Immune System
A man suffering stomach pains
Causes and Treatment of Colorectal Lymphoma
A doctor discussing medical chart with male patient
Aggressive Neuroendocrine Colon and Rectum Tumors
Colon cancer cell
Stages of Colon and Rectal Cancer
Senior man gestures while speaking with a healthcare provider.
Signs and Symptoms of Colon Cancer in Men
older man on toilet googling on his smart phone
Colon Cancer and Poop: Signs to Watch Out For
Doctor holding a colonoscope preparing for a colonoscopy
Adenomatous Polyp: Symptoms, Causes, Diagnosis, and Treatment
Colon cancer symptoms
Colon Cancer: Signs, Symptoms, and Complications
Doctor discussing prescription with senior patient
Common Causes of Colon Cancer Pain
Polyp removal, artwork
Colon Polyps Types and Symptoms
Smiling African American woman attaching earring
The Link Between Cancer and Low-Iron Anemia
Interior Of Bathroom
What Does a Bloody Stool Mean?
Rectal prolapse
Rectal Prolapse Signs, Diagnosis, and Treatment
a doctor reviewing medical chart with senior man
Is Rectal Itching a Sign of Cancer?
Close up of pants around businessman's ankles in restroom
Rectal Cancer Symptoms and Signs
Human colon, illustration.
The Best At-Home Colon Cancer Tests in 2021
Colon polyp being removed
Colon Polyp: Symptoms, Causes, Diagnosis, Treatment
Colon Cancer: Causes and Risk Factors
Cropped hand of laboratory technician holding blood sample for medical testing
Preventing Colon Cancer With Hereditary Lynch Syndrome
Hand refusing bread
Celiac Disease and Colon Cancer Risk
senior Asian couple reading book
Connection Between Age and Colorectal Cancer Risk
toilet paper
Bright Red Blood in Stool and Rectal Bleeding
Colon cancer stool screening test
Colon Cancer Screening: Tests and Recommendations
Doctor and Patient View Colon Cancer Screening Image.
Diagnosing Colon Cancer
PET Scan machine
PET Scans for Staging Colorectal Cancer
Man sitting on a toilet bowl
Colonoscopy: How to Prepare
Male patient and doctor in discussion in exam room
What to Expect From a Colon Biopsy
A rectal cancer cell
What Factors Influence Rectal Cancer Survival?
Fecal Occult Blood Test (FOBT): Uses, Procedure, Results
A slide on a lit up microscope
How a Colon Biopsy Is Performed
Technician holding blood sample for checking CEA in a patient with cancer
Carcinoembryonic Antigen (CEA) Blood Test: Uses and Results
Man talking with doctor
Stool Test Types and Options
Doctor sitting in office with patient talking and holding paper. Differences between colorectal and colon cancer
How Colorectal and Colon Cancer Differ
empty toilet paper rolls
How to Know When Bowel Prep Is Complete
Colon cancer screening
A Guide to Colon Cancer Screening for the Uninsured
Doctor talking to patient in office
What Is a False Positive Test Result?
A doctor goes over a patient''s x-ray, screening for colon cancer.
Barium Enema: Uses, Side Effects, Procedure, Results
Concerned young man
Young People and Colon Cancer Diagnosis
Doctor talking to patient in doctor's office
Anemia as a Signal of Colon Cancer
Doctor and patient discuss prognosis
Colon Cancer Prognosis, Survival Rates, and Life Expectancy
We need to get you started on the treatment immediately
Treatment of Colon Cancer
Close-up of surgeon putting on surgical gloves in operating theater
How to Prepare for a Proctectomy
Boiled egg
Low-Residue Diet: Benefits and How It Works
Woman drinking a glass of water in her kitchen
Colonoscopy: Recovery
Colostomy bags
Changing Your Colostomy Pouch
Page Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Cancer Society. Can colorectal cancer be prevented? Updated June 9, 2020.

  2. National Cancer Institute. Cancer stat facts: cancer of any site.

  3. Anderloni A, Jovani M, Hassan C, Repici A. Advances, problems, and complications of polypectomy. Clin Exp Gastroenterol. 2014;7:285-96. doi:10.2147/CEG.S43084

Additional Reading