Colon Polyps: 4 Warning Signs You May Notice During a Bowel Movement

Colon polyps are small growths that develop on the inner lining of the large intestine, or colon. They are relatively common, especially as people get older, and most colon polyps do not cause noticeable symptoms.

However, some types of polyps can eventually develop into colorectal cancer. That is why screening and appropriate follow-up are so important.

The image highlights warning signs that may appear during bowel movements. While these symptoms do not prove that someone has colon polyps, they can indicate bleeding, changes in the bowel, or another gastrointestinal condition that deserves medical attention.

Here are four changes you should know about.

1. Blood in Your Stool

One of the most important warning signs is blood associated with a bowel movement.

Blood may appear as bright red streaks on toilet paper or on the outside of the stool. Bleeding higher in the digestive tract can sometimes make stool appear dark, tarry, or almost black.

Colon polyps can bleed, although many polyps never produce enough bleeding to be visible.

It is also important to remember that blood in the stool has many possible causes.

For example, bright red blood can result from:

• Hemorrhoids
• Anal fissures
• Inflammation
• Certain intestinal infections
• Diverticular disease
• Polyps
• Colorectal cancer

Because the causes range from minor to serious, unexplained rectal bleeding should not automatically be attributed to hemorrhoids.

If bleeding is persistent, recurrent, heavy, or accompanied by other symptoms, arrange a medical evaluation.

2. A Persistent Change in Bowel Habits

Another potential warning sign is a new and persistent change in how often or how easily you have bowel movements.

You might notice that you are suddenly experiencing:

More frequent bowel movements

Constipation

Diarrhea

Alternating constipation and diarrhea

A noticeable change in stool consistency

Occasional changes are extremely common and can happen because of diet, stress, travel, medications, infections, or changes in fluid intake.

The concern increases when a bowel-habit change is new, unexplained, and persistent.

A large polyp can sometimes interfere with the normal passage of stool, although many polyps are too small to cause any mechanical symptoms.

If your usual bowel pattern changes and doesn't return to normal, it is worth discussing with a healthcare professional.

3. Narrower or Unusually Thin Stools

Some people become concerned when their stool appears thinner than usual.

There are many possible explanations for changes in stool shape, including temporary changes in bowel function, constipation, diet, or the way the stool passes through the rectum.

In some circumstances, however, persistent narrowing can occur when something affects the passage through the lower bowel.

A large polyp is one possible cause, but a thin stool by itself does not mean you have a colon polyp or cancer.

Pay more attention to a pattern that continues over time, especially if it occurs together with blood in the stool, abdominal discomfort, unexplained weight loss, or a persistent change in bowel habits.

4. Straining, Incomplete Emptying, or Persistent Changes During Bowel Movements

Another symptom worth paying attention to is the feeling that you still need to have a bowel movement even after you've just gone.

This sensation is sometimes called tenesmus.

A person may feel pressure or an ongoing urge to use the bathroom despite having little stool left to pass.

Other changes can include:

• Increasing difficulty passing stool
• Repeated straining
• A feeling of incomplete evacuation
• New urgency
• Unusual rectal pressure

These symptoms have many possible causes, including constipation, hemorrhoids, inflammatory bowel conditions, infections, and disorders affecting the rectum or colon.

A persistent unexplained change should be evaluated rather than assumed to be caused by a polyp.

Why Colon Polyps Matter

Colon polyps are not all the same.

Some are considered precancerous, meaning that certain types can gradually develop abnormal cellular changes and eventually become colorectal cancer.

Other polyps have little or no potential to become cancerous.

The risk depends on factors such as:

• The type of polyp
• Its size
• The number of polyps
• Its microscopic characteristics
• A person's age
• Family history
• Other medical factors

This is why doctors may recommend removing a polyp when it is discovered during a colonoscopy.

Removing certain precancerous polyps can help prevent colorectal cancer from developing.

Most Polyps Cause No Symptoms

This is perhaps the most important point.

A person can have colon polyps and feel completely normal.

There may be:

No pain

No bleeding

No constipation

No diarrhea

No noticeable change in bowel movements

That's why waiting for symptoms isn't an effective screening strategy.

Depending on age, personal medical history, family history, and other risk factors, healthcare professionals may recommend colorectal cancer screening even when someone feels perfectly healthy.

Screening can identify abnormalities before they produce noticeable symptoms.

Who May Have a Higher Risk?

The risk of colorectal polyps and colorectal cancer generally increases with age.

Other factors can also influence risk, including:

A family history of colorectal cancer or certain polyps

Previous colorectal polyps

Certain inherited genetic conditions

Inflammatory bowel disease

Smoking

Heavy alcohol consumption

Physical inactivity

Certain dietary patterns

Having a risk factor does not mean that someone will develop colorectal cancer.

Likewise, a person without obvious risk factors can still develop polyps.

What Happens During a Colonoscopy?

A colonoscopy allows a trained healthcare professional to examine the inside of the colon using a flexible camera.

If a polyp is discovered, it can often be removed during the same procedure.

The tissue can then be examined under a microscope to determine what type of polyp it is and whether additional monitoring is needed.

This is one reason colonoscopy is valuable: it can serve both as a screening examination and a method of removing certain potentially precancerous growths.

Other colorectal screening methods are also available, depending on the individual and local medical recommendations.

Don't Ignore Unexplained Rectal Bleeding

It's easy to assume that blood on toilet paper is simply caused by hemorrhoids.

Sometimes it is.

But because colorectal cancer and polyps can also cause bleeding, recurrent or unexplained blood should be discussed with a healthcare professional.

Seek urgent medical attention if you experience heavy rectal bleeding, dizziness, fainting, weakness, severe abdominal pain, or other symptoms suggesting significant blood loss.

When Should You See a Doctor?

Consider arranging a medical evaluation if you notice a persistent or unexplained change such as:

Blood in or on the stool

A lasting change in bowel habits

Persistent changes in stool shape or caliber

A recurring sensation of incomplete bowel emptying

Other symptoms that deserve attention include unexplained weight loss, persistent abdominal pain, ongoing fatigue, or symptoms of anemia such as unusual weakness or shortness of breath.

These symptoms do not automatically mean colon polyps or cancer.

They simply mean there may be a reason to investigate further.

The Bottom Line

Colon polyps are common, and many never cause symptoms. However, certain polyps can become precancerous, which makes appropriate colorectal screening extremely important.

Pay attention to persistent changes involving bowel movements, especially unexplained bleeding, lasting changes in bowel habits, persistent changes in stool form, or a recurring feeling that you haven't completely emptied your bowel.

But don't try to diagnose yourself based on one symptom—or a social-media image.

Hemorrhoids, constipation, infections, inflammatory conditions, medications, dietary changes, and many other problems can produce similar symptoms.

The goal isn't to assume the worst. It's to recognize persistent changes and get the right explanation.

If something about your bowel movements has changed and the change continues, talk with a healthcare professional. And if you're due for colorectal cancer screening, don't wait for symptoms to appear—screening is specifically designed to detect problems before they become obvious.