Woman going into the bathroom
Colon cancer is relatively common in the U.S. The American Cancer Society (ACS) estimates that it’s the third-most common cancer (excluding skin) and more than 106,000 people will be diagnosed with colon cancer in 2024 alone. The ACS notes that rates of new cases in people under 55 have been increasing by 1 to 2% each year. However, overall rates of colon cancer are decreasing—in large part because more people are being screened and tweaking habits to reduce their risks.
Screening is vital for another reason: Early detection of colon cancer can save lives.
“If colon cancer is detected early, the majority of patients are cured and can have normal lives,” says Dr. Anton Bilchik, MD, PhD, a surgical oncologist and the chief of medicine and director of the Gastrointestinal and Hepatobiliary Program at Providence Saint John’s Cancer Institute.
In addition to screening, flagging symptoms of colon cancer can also prompt early detection. Unfortunately, “Often, the symptoms of colon cancer are mistaken for other common things like Irritable Bowel Syndrome or hemorrhoids and then neglected,” says Dr. Rosario Ligresti, MD, the chief of the Division of Gastroenterology at Hackensack University Medical Center.
Doctors shared signs of colon cancer to never, ever ignore, plus insights on treatment options and prognosis.
The Common Color Cancer Sign You Should Absolutely Pay Attention To
GI doctors caution against ignoring blood in the stool. “Blood in the stool is one of the more common symptoms of colon cancer in older patients—less so in younger patients,” Dr. Ligresti says.
Why might colon cancer prompt blood in the stool? “As precancerous polyps, also known as adenomas, enlarge and become more abnormal and possibly progress towards becoming cancer, they require an increasing blood supply,” explains Dr. Brooks Cash, MD, a gastroenterologist with UTHealth Houston and Memorial Hermann. “Because adenomatous and cancerous tissue is immature and abnormal in terms of their cellular structures relative to normal colon tissue, the blood vessels that supply these lesions are also abnormal and are more prone to leak blood that may be visible in the bowel movements.”However, blood in the poop isn’t always apparent.
“It may result in dark stools, but a small amount of blood will only be detectable with special stool tests that detect very small amounts of blood,” Dr. Bilchik says.
In fact, by the time someone does flag blood in the stool, it may no longer be an “early symptom” of colon cancer. “Blood in the stool is a relatively late sign of colorectal cancer and does not present in every patient,” Dr. Cash says.
What Else Blood in the Stool Might Indicate
Noticing blood in your poop may be alarming, and understandably so. While it can be an early (or later) symptom of colon cancer, it may not be. “More commonly, it is due to lesions near the bottom of the colon, such as hemorrhoids or small tears called fissures,” Dr. Ligresti says. “It also could be coming from the urinary tract or vagina, which can sometimes be confused as rectal bleeding.”
Dr. Bilchik says that blood in the poop that is related to hemorrhoids is typically bright red. Regardless, this sign shouldn’t be brushed off. “Visible red blood in the stool is known as hematochezia and should never be ignored,” Dr. Cash says.
Other Potential Signs of Colon Cancer
Blood in the stool is one potential sign of colon cancer, but it’s not the only one to flag. Dr. Cash says other symptoms of colorectal cancer include:
- Unintentional weight loss
- Abdominal pain
- A change in bowel habits
- Signs that may be because colorectal cancer spreads to other organs beyond the colon, like seizures with brain metastases or fractures with bone metastases
Dr. Ligresti agrees that colon cancer signs aren’t always GI-related, explaining, “Younger patients also present commonly with unexplained anemia and associated fatigue. This might be hard to distinguish from anemia due to menstrual issues and, as always, check with your doctor. It is not normal to be anemic.”
There’s also a chance that you’ll have no symptoms at all. “People may have no symptoms at all, hence the importance of screening everyone over age 45, regardless of symptoms,” Dr. Bilchik says.
Treatment and Prognosis for Colon Cancer
It can’t be said enough: “If you notice blood in your stool, you should contact your healthcare provider and discuss your symptoms,” Dr. Cash says. “You may need to undergo an examination of the colon known as a colonoscopy.”
A colonoscopy is used to screen for colorectal cancer and other causes of blood in the stool. “If a precancerous polyp is found during a colonoscopy, it can often be removed, as can some colorectal cancers, depending on their size and location,” Dr. Cash explains.
Dr. Bilchik says surgical removal is generally the recommended route, sharing, “The best chance for cure is surgical removal. Chemotherapy, biological therapy and radiation therapy are often used in combination with surgery to improve the chances for cure. Depending on the presentation, these treatments can be given before or after surgery.”
During the process, you’ll likely have a large team of experts working to help you achieve the best outcomes. “Colon cancer is best treated by a team of doctors—gastroenterologists, surgeons, oncologists and radiation specialists,” Dr. Ligresti says.
And again, there’s good news regarding colon cancer’s prognosis if it’s caught early enough.
“Early colorectal cancer that is detected before it has spread through the wall of the colon or to other organs has a five-year survival of more than 90%,” Dr. Cash says. “The most advanced colorectal cancer is stage 4 and is identified when the cancer has spread to other organs. Stage 4 colorectal cancer has a five-year survival of less than 15%.”
