Colon Cancer Symptoms That Are Easily Overlooked

Colorectal cancer symptoms and early detection

Emily King of Mobile, Alabama, was diagnosed with colon cancer five years ago at the age of 27. She had experienced some diarrhea, abdominal pain and anemia, but having cancer had never entered her mind. Her first inkling that something might not be right was when she saw blood in her stool. Not long after, she had the cancerous tumor removed, along with a foot of her colon. Her doctors told her that the cancer had spread to 13 lymph nodes in her body.

King underwent 12 rounds of chemotherapy, after which she was told there were no signs of cancer. During a routine check-up six months later, she found out the cancer had reappeared. She underwent another 11 rounds of chemotherapy. Again, it seemed the cancer had disappeared, but three months later it had metastasized to the lungs. Now, she’s part of a clinical trial at Dana-Farber Cancer Institute in Boston and flies there every other week for treatment.

Colon cancer, mostly diagnosed in older people, is the second leading cause of cancer death and the third most common cancer in the United States. In recent years, it’s become the leading cause of cancer death in men under 50 and the second leading cause of cancer death in women under 50.

More young adults are being diagnosed with cancer, including colon cancer. By 2030, the incidence rate of colon cancer among young adults ages 20 to 34 in the U.S. is expected to increase by 90%.

“Many symptoms of colon cancer can be confused with other, more common conditions, which makes timely diagnosis challenging among young patients. Because some people have no symptoms at all, screening is recommended for individuals at average risk beginning at the age of 45,” says Dr. Kimmie Ng, chief of gastrointestinal oncology and director of the Young-Onset Colorectal Cancer Center at Dana-Farber in Boston. “One of our concerns, though, is that since the 1990s, we’ve seen an increase in colon cancer in people younger than 50, with the steepest rise seen is in those in their 20s and 30s.”

What is colon cancer?

Colon cancer results from an abnormal growth of cells that begins in a part of the large intestine called the colon. The colon is the first and longest part of the large intestine and is part of the body’s digestive system, which includes the esophagus, the stomach and the small and large intestines.

Most colon cancers develop from polyps (growths) in the colon’s inner lining, but not all polyps turn into cancer. Colon cancer screening with a stool-based test or colonoscopy is strongly recommended so that any found polyps can be removed before they can become cancer. If found early, cancerous polyps are very treatable and cancer is likely to be cured.

The U.S. Preventive Task Force recommends that adults at average risk start screening for colorectal cancer at age 45. This guideline was recently lowered from 50 due to the serious rise in young onset cases.

Symptoms of colon cancer

At the early stages of colon cancer, such as stage 1 colon cancer, there may be no symptoms.

Once they do appear, the presentation of the symptoms depends on the size and location of the tumor in the colon. Sometimes symptoms don’t appear until the cancer has grown or spread, emphasizing the need for early and regular screening. Symptoms of colon cancer are the same for everyone, regardless of gender.

Additionally, some of the symptoms can mimic those of other less serious conditions. For example, blood in the stool can often be mistaken for hemorrhoids.

Unfortunately, doctors tend to attribute colon cancer symptoms to other, less serious conditions, and colonoscopies for people under the age of 45 are difficult to access, which can lead to missed diagnoses, says Dr. Nicholas DeVito, a medical oncologist and assistant professor of medicine at Duke Cancer Institute.

In an era when there is rising early-onset colon cancer, this can be extremely problematic.

To counter this kind of situation that happens all too often, DeVito urges patients to find out what their symptoms may mean and to advocate fiercely for themselves.

“Instead of simply treating symptoms, doctors need to spend more time trying to determine why patients have those symptoms,” DeVito says.

Here are the six most common colon cancer symptoms:

1. Blood in the stool

The way your stool looks can be a good indicator of what’s going on in your body. If you see blood in the toilet or on toilet paper after wiping or blood mixed in with the stool, don’t ignore it. Blood in the stool or darker colored bowel movements could indicate bleeding in the intestinal tract.

In fact, blood in the stool is the most common symptom of colon cancer among young people, according to Ng.

If there are precancerous polyps or cancerous tumors in the colon, stool can mix with blood as it passes through the digestive tract and cause it to appear dark brown or black.

Bleeding in the intestinal tract can also be present, but not visible. Hidden blood may not be discovered until a blood test indicates a low red blood cell count.

2. Changes in bowel habits

In healthy people, bowel movements typically produce stool that is brown, soft, well-formed and easy to pass. Changes in size, shape and frequency, and discomfort or pain while having a bowel movement may be an indication of a problem.

Constipation. Constipation is having less than three bowel movements a week. It occurs when stools become difficult to pass. Often, it happens due to diet and routine or inadequate intake of fiber. If it lasts longer than a few weeks, consult with a physician.

Diarrhea. Diarrhea means having loose, watery stools that may cause you to have to go to the bathroom often. It can be caused by a virus, certain foods and by many other factors. If it persists, don’t ignore it. It’s likely not colon cancer, but it is one of the symptoms.

Small bowel movements. Pencil-like and small thin bowel movements could indicate narrowing of the colon due to a cancerous tumor.

Flat stool. Flat or ribbon-like stool could indicate a tumor, which could change the shape of the colon.

Mucus in stool. Mucus in stool is caused by a gel-like substance secreted by the intestines that help the stool pass through the colon. A small amount in the stool is normal, but an excess is not and could be indicative of a problem.

3. Abdominal pain and bloating

Stomach bloating, distention, cramps or pain in the abdominal bowel region with no known cause that doesn’t go away may be a symptom of colon cancer. They can also be the signs of many other conditions, but if they persist, seek medical attention.

Depending on where a tumor is located, it can cause obstruction or blockage in the colon that can result in serious pain, usually in the lower left abdomen.

4. Anemia

Intestinal bleeding may cause anemia in people with colon cancer. Depending on the location of the bleeding in the colon, anemia can be the first sign that blood loss is occurring. When a colon cancer tumor bleeds, that causes iron loss in the body, which leads to anemia.

Anemia occurs when levels of healthy red blood cells are low or there’s not enough hemoglobin, a protein found in red blood cells, to carry oxygen to the body’s organs and tissues. Symptoms include paleness, increased heart rate, fatigue, dizziness and irregular menstruation.

As with all other symptoms, anemia should not be dismissed. The cause of blood loss should be determined, as it can be colon cancer or another serious condition.

5. Nausea and vomiting

Nausea and vomiting, like all symptoms of colon cancer, can also be symptoms of other problems. If you’re vomiting for no reason and it continues for 24 hours, you should seek medical attention.

This can happen if a colon tumor is obstructing the bowel and blocking the passage of solid or liquid waste or gas. Persistent vomiting can also lead to dehydration and more complications.

6. Unintentional weight loss

Unexplained weight loss, especially if it’s significant or ongoing, should not be ignored, as it can be a sign of colon cancer. That’s because some tumors release chemicals that speed up the body’s metabolism, causing weight loss.

You should seek medical attention if you lose more than 5% of your weight in a six- to 12-month time frame without intentionally trying to do so.

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Colon Cancer Symptoms That Are Easily Overlooked originally appeared on

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