Colon / Colorectal cancer
Blood in stool, on toilet paper, or in the toilet bowl
Visible blood: bright red on the paper, streaked through stool, or in the bowl. Also counts: dark, tarry, sticky stools (this suggests bleeding higher up in the digestive tract). Also counts: iron-deficiency anemia showing up on bloodwork without an obvious cause.
What it could mean
Colorectal cancer rates in adults under 50 have nearly doubled since the 1990s. Rectal bleeding is one of the earliest and most-dismissed signs. If you’re under the recommended screening age (45 per current USPSTF guidance), your doctor is statistically likely to write this off as hemorrhoids without ruling anything out.
What it probably is (to be fair)
Most rectal bleeding is hemorrhoids, anal fissures, or diet-related irritation. That is genuinely true. But "probably" is not "definitely," and only a scope tells you the difference.
Why this gets dismissed
If you’re under 45 with rectal bleeding, you WILL be told it’s hemorrhoids. This is not a fluke. It is the default. "You’re young" gets treated as a diagnosis when it isn’t one.
Younger colorectal cancer patients wait an average of 6 months longer for diagnosis than older patients. Not because the science is harder. Because their symptoms are dismissed on sight. You do not need to be polite about this.
The exact ask: "I want this ruled out with a physical exam and a colonoscopy referral if warranted. Not next year. Now." If your doctor won’t refer, get a second opinion or request a GI consult directly.
When to call your doctor
- Any rectal bleeding lasting more than a few days
- Any change in bowel habits (constipation, diarrhea, thin stools) lasting 3+ weeks
- Unexplained weight loss (more than 5% of body weight without trying)
- Persistent abdominal cramping, gas, or the feeling that your bowel doesn’t empty completely
- New iron-deficiency anemia on bloodwork without a clear cause (heavy periods excepted)
- Extreme fatigue that isn’t explained by sleep or life
When to go to the ER
- Heavy bleeding (soaking through pads, filling the bowl, or with clots)
- Dizziness or lightheadedness with the bleeding
- Dark tarry stools with fatigue or lightheadedness (signals significant blood loss)
- Severe abdominal pain, especially with fever or vomiting
If you're dismissed
Ask directly: "Can you rule this out with a rectal exam and, if needed, a colonoscopy referral?" You are allowed to insist. If they refuse, request the refusal in writing. This almost always changes the answer. You can also self-refer to most GI practices with a doctor’s note, or through direct-access screening programs like ColonoscopyAssist.com.
If it runs in your family
If a first-degree relative had colorectal cancer, your screening age drops to 10 years before their diagnosis, or age 40, whichever comes first. Lynch syndrome and familial adenomatous polyposis push it earlier still. Push for a colonoscopy referral even if you’re under 45. This is your birthright, not a favor.
