Colon & Rectal Cancer Symptoms

Colon & Rectal Cancer Symptoms as Described by Real Cancer Patients

Colorectal cancer, colon cancer, and rectal cancer symptoms vary and can show up differently for each person. Sometimes, especially for earlier stage (1, 2) cancer, there are no symptoms at all.

Very importantly, many people will experience some of these symptoms, and it will not be cancer. According to the National Cancer Insitute, other common causes may be other gastrointestinal illnesses, such as:

  • influenza
  • ulcers
  • colitis

Below is what how our colon cancer patients describe symptoms, along with guidelines from the National Cancer Institute. This is to give real patient examples and is not a substitute for medical advice.

If you are feeling any symptoms, please check in with a doctor, especially if symptoms last more than two weeks.


Symptoms of colon cancer
  • Change in your bowel habits like diarrhea, constipation
  • Change in stool consistency, narrower than usual
  • Blood in/on your stool (bright red or very dark)
  • Stomach pain, discomfort, aches, bloating, fullness, or persistent cramps
  • Weight loss (unexplained)
  • Fatigue, feeling very tired
  • Vomiting
  • No symptoms
    • Colon and colorectal cancer may not show symptoms, especially in the beginning stages. This is why the NCI advocates getting screened regularly. This is how Shannon Mercurio discovered her stage 1 colon cancer.

Patients describe colorectal cancer symptoms

Stomach pain

Barbara Majeski says she knew something was wrong when she started to feel stomach discomfort, especially after a meal.

I found it really hard to process food. Things were just sitting in my gut. It was starting to get really really uncomfortable.

Then I just started to take out wheat and dairy and puree my foods, getting a real sense of this is not right. We all have intuition. My intuition was like, this ain’t going well.”

Barbara Majeski, Stage 3 Colon Cancer

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For Shannon Costello, it was also stomach pains that eventually sent her to seek medical attention.

I was having severe pain after I would eat out. 20 minutes after it is just excruciating and I have a very high tolerance for pain. So I thought, you know, maybe it was something with my diet, something wasn’t sitting right…

Then it started getting worse really quickly. Really bad. I was starting to get very tired but I wrote that off as having two young kids and working full time.

Shannon Costello, Stage 2A Colon Cancer

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Weight loss

Lindsay Danneker had a few symptoms, like a lump in her pelvic area and food started to smell funny, but it was the weight loss with some pain that really drove her to figure out what was going on.

I usually range about 115 to 120 (pounds). And I had gotten down to like 95 pounds. I dropped a lot of weight really fast and so I knew something serious was happening.

Lindsay Danneker, Stage 4 Colon Cancer

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Blood in stool

Rachel Braga says she felt something wasn’t right with her body and her health, but it wasn’t until she found blood during a bowel movement that she realized she needed to see a doctor.

I was nauseous and bloated all the time. My stomach just felt really off.

The straw that broke the camel’s back was finding blood in my stool. 

Rachel Braga, Stage 1 Colon Cancer

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No symptoms (early screening)

For Chris Tarver, a known family history of cancer helped him understand that he would need to get screening done earlier than usual.

I just went in for that routine colonoscopy, and once they were done, they basically told me I had colon cancer and they didn’t know the stage or anything because at that point, I didn’t have scans.

Chris Tarver, Stage 2 Colon Cancer

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My story might be a little different in that I didn’t have any symptoms. I didn’t know anything was wrong. I had just turned 36, and my daughter had just turned one.

I was going in for a routine colonoscopy because I have something called Lynch syndrome, which is a genetic mutation that puts me at really increased risk for a lot of different cancers. Colon cancer is one of them.

I’d just had one a year before, but it was clear. I was pretty shocked to find out the next one wasn’t quite normal. The process went from there.

Shannon Mercurio, Stage 1 Colon Cancer, Related to Lynch Syndrome

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