If You Have Colon Polyps, 4 Warning Signs to Watch for During Bowel Movements

Colon polyps are small growths that develop on the inner lining of the colon or rectum. Most colon polyps do not cause symptoms, and many are discovered unexpectedly during routine screening colonoscopy.

That is exactly why screening matters.

Some types of polyps can gradually develop into colorectal cancer over a period of years. Finding and removing certain precancerous polyps can reduce the chance that they progress. However, having a polyp does not automatically mean you have cancer.

While many polyps remain silent, there are several bowel-related changes that should prompt medical attention—especially if they are new, persistent, or unexplained.

Here are four important warning signs to know.

1. Blood in Your Stool

One of the most important changes to watch for is blood during or after a bowel movement.

You might notice bright-red blood on the toilet paper, streaks of blood on the stool, or blood mixed with stool. In other cases, bleeding can occur higher in the digestive tract and make the stool appear unusually dark or black.

Colon polyps can sometimes bleed slowly.

However, blood in the stool does not automatically mean you have colon polyps or cancer. Hemorrhoids, anal fissures, infections, inflammatory bowel disease, and other conditions can also cause rectal bleeding.

Still, unexplained rectal bleeding should not simply be assumed to be hemorrhoids.

If bleeding keeps happening, becomes heavier, or is accompanied by other symptoms, arrange a medical evaluation.

2. A Persistent Change in Bowel Habits

Everyone's bowel habits vary.

You might occasionally experience constipation after changing your diet or diarrhea after eating something that doesn't agree with you. A short-term change is usually not alarming.

The concern is a persistent change from your normal pattern.

This can include:

• Constipation that continues longer than usual
• Frequent diarrhea
• Alternating constipation and diarrhea
• A noticeable change in stool frequency
• An unusual change in the appearance or consistency of your stool

A persistent change doesn't necessarily indicate a polyp. Diet, medications, infections, irritable bowel syndrome, thyroid problems, and many other conditions can affect bowel habits.

But when a change is new, unexplained, and persistent, it's worth discussing with a healthcare professional.

3. Narrower or Unusually Shaped Stools

You've probably heard the claim that "pencil-thin stools always mean colon cancer."

That's too simplistic.

Stool shape can naturally vary depending on diet, hydration, bowel movements, and other factors. A temporary change in stool shape is generally not enough to indicate a serious disease.

However, if you notice a persistent change in the caliber or shape of your stool, particularly when it occurs alongside bleeding, abdominal discomfort, unexplained weight loss, or changes in bowel habits, it deserves medical attention.

A growth inside the colon can sometimes affect the passage of stool, although this is not specific to polyps and can occur with other conditions as well.

The key is not to panic over one unusual bowel movement.

Pay attention to patterns that persist.

4. Feeling Like You Haven't Completely Emptied Your Bowels

Another symptom that deserves attention is the repeated sensation that you still need to have a bowel movement even after you've gone.

This feeling is sometimes called tenesmus.

You may experience:

• Repeated urges to use the bathroom
• Passing only a small amount of stool
• Straining
• Feeling that something remains in the rectum
• Repeated bowel movements without feeling relieved

There are many possible explanations, including constipation, hemorrhoids, inflammation, infections, and other gastrointestinal disorders.

In some cases, abnormalities in the rectum or colon can contribute to these symptoms.

If this sensation persists or is accompanied by bleeding, pain, unexplained weight loss, or a major change in bowel habits, medical evaluation is important.

Why Colon Polyps Matter

Colon polyps are not all the same.

Some are hyperplastic polyps, which generally have a very low risk of becoming cancerous. Others, including certain adenomas and serrated lesions, can have the potential to become colorectal cancer over time.

The risk depends on factors such as:

• Polyp type
• Size
• Number of polyps
• Location
• Microscopic characteristics
• Personal and family history

This is why doctors may recommend follow-up colonoscopies at different intervals depending on what was found.

A polyp discovered during colonoscopy can often be removed during the same procedure.

The removed tissue is then examined by a pathologist to determine exactly what type of polyp it is and whether it contains precancerous changes.

Don't Wait for Symptoms to Get Screened

One of the biggest misconceptions about colorectal cancer is that you will necessarily experience obvious symptoms before something serious develops.

You may not.

Precancerous polyps frequently cause no symptoms at all.

That means waiting for blood in the stool or changes in bowel movements isn't an ideal screening strategy.

For people at average risk, colorectal cancer screening generally begins in adulthood according to current guideline recommendations, with the exact age and screening method depending on the guideline and individual circumstances.

People with a family history of colorectal cancer or advanced polyps, certain inherited conditions, inflammatory bowel disease, or other risk factors may need earlier or more frequent screening.

Your healthcare professional can help determine the appropriate schedule.

When Should You See a Doctor?

Make an appointment if you experience persistent or unexplained:

Rectal bleeding

Changes in bowel habits

Changes in stool appearance

Abdominal pain or cramping

Unexplained weight loss

Persistent fatigue

A feeling of incomplete bowel emptying

These symptoms have many possible causes, and most do not automatically indicate cancer.

But they deserve attention when they persist.

Seek urgent medical care for heavy rectal bleeding, black or tarry stools accompanied by concerning symptoms, severe abdominal pain, repeated vomiting, fainting, or symptoms suggesting significant blood loss or bowel obstruction.

What You Can Do to Protect Your Colon

There is no guaranteed way to prevent every colon polyp, but several lifestyle habits are associated with better colorectal health.

A balanced diet rich in vegetables, fruits, legumes, and whole grains provides dietary fiber and a variety of nutrients.

Regular physical activity is also beneficial.

Other important habits include maintaining a healthy weight, avoiding tobacco, limiting alcohol, and following recommended colorectal cancer screening.

If you've previously had polyps removed, don't skip your recommended follow-up colonoscopy. Surveillance is based on your individual findings and is an important part of reducing future risk.

The Bottom Line

Colon polyps are common, and most do not cause noticeable symptoms.

However, persistent changes during bowel movements—including rectal bleeding, significant changes in bowel habits, persistent changes in stool caliber, and a recurring feeling of incomplete evacuation—should not be ignored.

These signs do not prove that you have colon polyps or colorectal cancer. They can result from many other conditions.

But they are good reasons to speak with a healthcare professional.

And remember: screening is especially important because potentially precancerous polyps can exist without causing any symptoms.

Don't wait for your body to send a dramatic warning.

Know your normal bowel habits, pay attention to persistent changes, and stay up to date with recommended colorectal screening.