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What stage of colon cancer is blood in stool?

Finding blood in your stool can be an alarming symptom. While there are many potential causes, one possibility is colon cancer. Knowing the stages of colon cancer can help determine how advanced the disease may be if blood is present.

Stages of Colon Cancer

Colon cancer is staged based on the extent of the disease using the TNM system:

  • T describes the extent of spread to the layers of the colon wall
  • N indicates spread to nearby lymph nodes
  • M means metastasis or spread to distant organs like the liver or lungs

Here are the main stages of colon cancer:

Stage Description
Stage 0 Cancer is in its earliest stages and limited to the inner lining of the colon
Stage I Cancer has grown into deeper layers of the colon wall but hasn’t spread to lymph nodes or other organs
Stage II Cancer has grown into the wall of the colon and may have spread to nearby tissue but still hasn’t spread to lymph nodes
Stage III Cancer has spread to nearby lymph nodes but not yet to other organs
Stage IV Cancer has spread to distant sites like the liver or lungs

Blood in Stool and Colon Cancer Stages

So what colon cancer stage is most likely if you have noticed blood in your stool?

Here is an overview of when blood in stool may occur with each stage:

  • Stage 0: Rarely causes blood in stool
  • Stage I: May begin to cause traces of blood, often not visible
  • Stage II: More likely to cause intermittent blood, may be visible at times
  • Stage III: Routinely causes blood; often visible in stool
  • Stage IV: Frequent visible blood is common

As you can see, blood in the stool becomes more common and noticeable as colon cancer progresses to later stages.

What Does Blood in Stool Look Like?

The appearance of blood in your stool may also give clues as to potential colon cancer stages:

Appearance Description Indication
Streaks of blood Thin streaks of blood in or on stool Potential small polyps or early stage cancer
Spots of blood Small spots or drips of blood in stool Potential small polyps or early stage cancer
Mixed with stool Stool appears reddish or maroon Potential later stage cancer and internal bleeding
Coating stool Blood coats or drips off of stool Potential later stage cancer and bleeding mass

While traces of blood may indicate benign polyps or early stage cancer, visible coating of blood on stool likely signals a later stage tumor that is actively bleeding.

What Else Can Cause Blood in Stool?

While colon cancer is one potential cause, there are other conditions that can result in blood in the stool as well. These include:

  • Hemorrhoids
  • Anal fissures
  • Diverticulosis
  • Angiodysplasia
  • Ulcerative colitis
  • Crohn’s disease
  • Celiac disease
  • Peptic ulcers
  • Intestinal infections

Many of these tend to cause sporadic traces of visible or invisible blood. Persistent visible blood, especially later in life, requires colon cancer screening.

When to Seek Evaluation for Blood in Stool

The American Cancer Society recommends seeking prompt medical evaluation if you notice the following:

  • Blood in or on your stool
  • Blood coating or dripping off stool
  • Changes in stool color to reddish or black
  • Constant diarrhea or constipation
  • Narrower than normal stool
  • Abdominal pain, bloating or cramps

Evaluation is recommended starting at age 45, or earlier if you have other colon cancer risk factors. Testing may include:

  • Medical history and exam
  • Fecal immunochemical test
  • Flexible sigmoidoscopy
  • Colonoscopy and biopsy

Based on test results, your doctor can determine if cancer is present and if so, the stage. Early detection provides the best outcomes.

Can Colon Cancer Be Found Early?

Colon cancer can often be found at an early, treatable stage through proper screening:

Screening Test Frequency
Colonoscopy Every 10 years beginning at age 45
Flexible sigmoidoscopy Every 5 years beginning at age 45
CT colonography Every 5 years beginning at age 45
Fecal immunochemical test Yearly beginning at age 45
Stool DNA test Every 3 years beginning at age 45

Screening allows detection of precancerous polyps that can be removed before turning into cancer. Screening is recommended earlier and more frequently for those at higher risk.

Colon Cancer Survival Rates by Stage

Survival rates give an indication of prognosis at different stages of colon cancer:

Stage 5-Year Relative Survival Rate
Stage 0 90%
Stage I 92%
Stage IIA 87%
Stage IIB 63%
Stage IIC 63%
Stage IIIA 89%
Stage IIIB 69%
Stage IIIC 53%
Stage IVA 18%
Stage IVB 6%

As shown, early stage colon cancer treated promptly has a high 5-year survival rate. Later stage colon cancer that has spread has a much lower survival outlook.

Treatment Options by Stage

Colon cancer treatment depends on the stage and may include:

Stage Treatment Options
Stage 0 Polypectomy during colonoscopy
Stage I Surgery to remove section of colon and nearby lymph nodes
Stage II Surgery plus chemotherapy
Stage III Surgery, chemotherapy, radiation therapy
Stage IV Chemotherapy, radiation, targeted drug therapy

While early stages may only require minor surgery, later stages often need a combination of aggressive therapies.


Blood in the stool can result from colon cancer, especially as the disease progresses to later stages. Notify your doctor promptly with any change in bowel habits or blood present. Cancer found early through screening provides the best chance for remission and survival. Maintaining recommended colon cancer screening beginning at age 45 offers the best opportunity for detection and successful treatment.