How To Tell The Difference Between IBS And Colon Cancer

Irritable bowel syndrome (IBS) is a chronic condition of your gut, including your large intestine or colon. Colon cancer develops when you have tumors developing in your large intestine. Colorectal cancer can also be found in your colon or rectum.

Since colon cancer and IBS affect the same part of your body, they may have similar symptoms. If you are experiencing some of these symptoms, it’s essential that you know the difference between the two so you can take appropriate action as early as possible.

Have you considered clinical trials for Irritable bowel syndrome (IBS)?

We make it easy for you to participate in a clinical trial for Irritable bowel syndrome (IBS), and get access to the latest treatments not yet widely available - and be a part of finding a cure.

Can IBS be confused with colon cancer?

Being concerned about colon cancer is understandable. Unlike irritable bowel syndrome, most cases of colon cancer occur in individuals over 50 years old, although there has recently been an increase in cases in younger people¹.

It’s easy to get IBS confused with numerous other gastrointestinal conditions, including colon cancer. Knowing the difference between the two is important so you can get treated as early as possible.

How to tell the difference between IBS and colon cancer

The symptoms of colon cancer might not become noticeable until cancer has already spread. This is why colonoscopy and other screening methods remain important. This type of cancer is usually, but not always, slow-growing.

IBS symptoms mimic those of colon cancer, particularly altered bowel movements and pain. However, with IBS, individuals may find whitish mucus in their stool, which doesn’t generally occur with colon cancer.

There are a few symptoms that can help you identify colon cancer. These include:

  • Rectal bleeding, either presenting itself as dark blood or bright red blood mixed with your stool

  • Abdominal pain that worsens over time or continuously changes in character

  • Unexplained weight loss 

  • Persistent change in your bowel habits, including constipation or diarrhea, or a change in the shape (narrowing) or consistency of your stool

  • General weakness

  • Vomiting

  • Fatigue

Vomiting and bloody stools are not signs of IBS, while whitish mucus in the stool is not a symptom of colon cancer.

Is there a link between having IBS and developing colon cancer?

IBS, with all its inconvenience and discomfort, doesn’t cause digestive tract damage or lead to other health issues.

A 2010 trial found that when individuals with IBS underwent colonoscopy, they were no more likely to experience structural irregularities of their colon than healthy individuals². The trial also found that individuals with IBS don’t have a higher risk of colon cancer or precancerous polyps.

How is colon cancer diagnosed?

Screening is important since colon cancer typically doesn’t cause symptoms in its early stages. It allows doctors to detect cancer before it begins causing symptoms; this is when it is most curable. When you reach the age of 45, you should start getting a colonoscopy screening every 10 years³. A colonoscopy allows doctors to examine your entire colon and rectum. It helps find cancers in their early stage when they’re more treatable and allows surgeons to remove polyps, preventing cancers from developing.

If the doctor finds abnormalities in your colon or rectum, they will do a biopsy to determine if there is cancer present. They’ll examine the tissue microscopically to check for cancer cells.

When should you see a doctor?

The American Cancer Society recommends that if you are experiencing abdominal pain or notice any significant bowel movement changes, you should seek medical advice⁴. These IBS symptoms can also indicate other serious underlying diseases, including colon cancer.

Aside from the above, you should also seek advice from your doctor if you’re experiencing the following symptoms:

  • Rectal bleeding

  • Persistent abdominal pain

  • Weight loss

  • Vomiting

The lowdown

Yes, it is important to know how to tell the difference between IBS and colon cancer. However, you should still take any symptoms seriously. While IBS doesn’t raise your chances of developing a more serious condition, it doesn’t mean you shouldn’t be concerned about it. Always consult your doctor about new symptoms like narrowed stool, rectal bleeding, or weight loss.

You should also consult your doctor about getting screened for colon cancer, especially if you have risk factors like family history. Your doctor might recommend you get screened earlier and more frequently.

You can generally manage IBS by making certain lifestyle and dietary changes. More serious cases, however, might require medication.

Because symptoms of colon cancer, IBS, and other gastrointestinal disorders overlap, it’s best to not hesitate to see your doctor for the right diagnosis.

Have you considered clinical trials for Irritable bowel syndrome (IBS)?

We make it easy for you to participate in a clinical trial for Irritable bowel syndrome (IBS), and get access to the latest treatments not yet widely available - and be a part of finding a cure.

Joining community groups and exercise programs for my condition made me feel empowered – but I want to be part of finding a cure.
Peter, 64

Have you considered clinical trials for Irritable bowel syndrome (IBS)?

Do you want to know if there are any Irritable bowel syndrome (IBS) clinical trials you might be eligible for?
Have you taken medication for Irritable bowel syndrome (IBS)?
Have you been diagnosed with Irritable bowel syndrome (IBS)?

Editor’s picks


Join our email list

Want all the latest clinical trial and HealthMatch news in your inbox? We thought you might! Sign up below.