“I feel well. Should I be checked?”
Screening looks for colorectal cancer or precancerous polyps in people who do not have symptoms. For most average-risk adults, routine screening begins at age 45.
Compare screening options →Screening vs diagnosis
Screening is for people without symptoms. Symptoms change the question.
A home screening test is not a substitute for evaluation when you are already having concerning symptoms.
“I have a symptom. What is causing it?”
When symptoms are present, clinicians use diagnostic evaluation to determine the cause. The appropriate testing can differ from routine screening.
Find GI care →CDC-listed symptoms
Symptoms that deserve medical discussion
- Change in bowel habits
- Blood in or on the stool
- Diarrhea, constipation, or feeling the bowel does not empty completely
- Abdominal pain, aches, or cramps that do not go away
- Unexplained weight loss
- Low iron levels / iron-deficiency anemia
These symptoms can have many causes other than cancer. The point is not to panic—it is to get the cause evaluated rather than self-diagnosing.
Seek urgent medical attention for heavy or ongoing bleeding, fainting, severe or worsening abdominal pain, breathing difficulty, chest pain, or other severe symptoms.
No symptoms does not mean no risk.
Polyps and colorectal cancer do not always cause symptoms. That is why regular screening matters even when you feel completely well.
Evidence
Primary sources for this page
Medical content reviewed against these sources on September 5, 2026. External clinician review is still recommended before broad public promotion.