When blood repeatedly appears during bowel movements, arrange a medical assessment rather than waiting for the symptom to disappear.
Heavy bleeding, fainting, severe weakness, or signs of circulatory instability require emergency medical attention.
4. Warning Sign Number Two: Persistent Changes in Bowel Habits
Another potential warning sign is a noticeable change in normal bowel habits.
Some people who previously had regular bowel movements begin experiencing persistent constipation.
Others develop frequent diarrhea or alternate between constipation and loose stools.
These changes can occur for many reasons.
Dietary changes, dehydration, medications, infections, irritable bowel syndrome, and other digestive conditions may all influence bowel movements.
However, persistent unexplained changes can sometimes be associated with colorectal polyps or cancer.
A large polyp or tumor may affect the passage of stool through the intestine.
Depending on its location and size, it may contribute to narrowing or partial obstruction.
People should pay attention when bowel habits change and remain abnormal for several weeks.
Examples include:
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Constipation that becomes increasingly frequent.
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Diarrhea that does not resolve.
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Alternating constipation and diarrhea.
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A noticeable change in normal stool frequency.
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Persistent urgency to have a bowel movement.
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Unexplained changes in stool consistency.
These symptoms do not automatically indicate cancer.
Nevertheless, persistent changes deserve investigation, particularly in adults with additional risk factors.
5. Warning Sign Number Three: Narrow or Unusually Thin Stools
Some people become concerned when their stools appear narrower than usual.
In certain circumstances, a growth inside the colon may partially narrow the intestinal passage.
This can change the shape or size of stool.
However, stool shape is influenced by many factors, including bowel movement patterns, constipation, intestinal spasms, and dietary habits.
Occasionally passing thin stool is not enough to establish the presence of a colon polyp or tumor.
The concern is greater when a persistent change occurs alongside other symptoms.
These may include:
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Blood in the stool.
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Unexplained weight loss.
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Abdominal discomfort.
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Persistent constipation.
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A feeling of incomplete bowel emptying.
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Unexplained fatigue.
A narrowing of the intestinal passage caused by a significant growth may eventually lead to partial or complete obstruction.
Severe abdominal pain, vomiting, marked abdominal swelling, and inability to pass stool or gas can indicate an emergency.
These symptoms require immediate medical evaluation.
Do not use stool shape alone to diagnose colon cancer. Look at persistent changes together with the overall clinical picture.
6. Warning Sign Number Four: A Feeling That Your Bowel Has Not Completely Emptied
Another symptom that deserves attention is the persistent sensation that stool remains inside the rectum after a bowel movement.
This feeling is sometimes called tenesmus.
A person may visit the bathroom, pass stool, and still feel the urge to go again shortly afterward.
The sensation may occur repeatedly, even when very little stool is passed.
Several conditions can cause this symptom.
These include:
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Rectal inflammation.
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Inflammatory bowel disease.
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Rectal polyps.
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Colorectal tumors.
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Certain infections.
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Pelvic floor dysfunction.
A growth located in the rectum may sometimes create pressure or irritation that produces a sensation of incomplete evacuation.
However, tenesmus is not specific to colon polyps.
If the sensation persists, particularly when accompanied by bleeding, pain, or changes in bowel habits, a medical examination is appropriate.
7. Why Colon Polyps Often Develop Without Symptoms
One of the most concerning characteristics of colon polyps is that they frequently remain silent.
A person may have an adenoma for years without experiencing pain, bleeding, or any noticeable change in bowel movements.
Small polyps are particularly unlikely to cause obvious symptoms.
Even larger growths may not produce noticeable problems until they begin bleeding or affecting the passage of stool.
This explains why waiting for symptoms is not an effective screening strategy.
Colorectal cancer screening aims to identify abnormalities before symptoms appear.
Colonoscopy is particularly useful because it allows doctors to examine the colon directly and remove many polyps during the same procedure.
Early detection can help prevent certain precancerous lesions from progressing to cancer.
8. How Can a Colon Polyp Become Cancerous?
Most colorectal cancers develop through a gradual process involving changes in the cells lining the colon or rectum.
One well-known pathway is the adenoma-carcinoma sequence.
Initially, normal cells develop genetic changes that cause abnormal growth.
A small adenoma may form.
Over time, additional genetic alterations can cause the cells to develop increasingly abnormal characteristics.
In some cases, these changes eventually lead to invasive cancer.
This process often takes years, although the timeline varies.
Not every adenoma progresses to cancer.
The likelihood depends on several factors, including:
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Polyp size.
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Polyp number.
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Histological type.
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Degree of dysplasia.
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Genetic characteristics.
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Individual risk factors.