What you should know about the IBS and colon cancer connection

Colon cancer symptoms

Irritable bowel syndrome (IBS) and colon cancer share some symptoms in common, however IBS does not put a person at an increased risk of colon cancer.

Irritable bowel syndrome (IBS) is a chronic condition that causes stomach discomfort and other symptoms. The big intestine, often known as the colon, is affected by this condition.

Colon cancer affects the same region as IBS, and in some people, it can cause many of the same symptoms.

The similarities and differences between IBS and colon cancer symptoms are discussed in this article.

Colon cancer symptoms

Colon cancer symptoms

Symptoms of colon cancer may not always be caused immediately. The onset of symptoms might take several years. Several illnesses, according to the American Cancer Society, can cause symptoms that are similar to colon cancer and should be checked out during diagnosis.

According to the article, the following are some of the most prevalent symptoms of colon cancer:

  • unexplained weight loss
  • weakness or fatigue
  • rectal bleeding bright red blood
  • dark brown or black blood in stool
  • abdominal pain or cramping
  • change in bowel habits, including a narrowing of the stool, diarrhea, or constipation that lasts for more than just a few days
  • feeling a need to pass a bowel movement without relief

IBS symptoms 

One or more symptoms may be present in people who have IBS. The following are some of the most prevalent IBS symptoms:

  • abdominal pain, often related to bowel movements
  • changes in bowel movements, which can include constipation, diarrhea, or possibly both

Around the time of their period, those who were designated female at birth may notice an increase in the severity of their symptoms.

IBS can also cause the following symptoms:

  • bloating
  • feeling as though a bowel movement is not finished
  • whitish mucus in stool

Despite the fact that IBS might be uncomfortable, it does not cause additional gastrointestinal (GI) tract issues.

Comparison table of symptoms 

Although IBS and colon cancer have certain symptoms, there are several important distinctions to be aware of. The table below lists both colon cancer and IBS symptoms, as well as symptoms specific to each condition.

SymptomColon cancerIBS
excess gas or bloatingXX
pain or cramps in abdomen associated with bowel movementsXX
feeling of incomplete bowel movementXX
changes in bowel movements and habits lasting more than a few daysXX
unexplained weight lossX
bleeding from rectumX
stool appears narrowX
dark stool or blood in stoolX
a whitish mucus appears in stoolX

Connection between IBS and colon cancer

IBS can cause stomach pain and discomfort. It does not, however, raise the risk of colon cancer since it does not cause inflammation or other harm to the GI tract.

Researchers found similar results in a 2010 trial analysis of over 900 people. They discovered that people with suspected IBS had the same risk of cancer as those who had normal bowel movements.


To diagnose IBS, a doctor may not need to do diagnostic tests. If they suspect anything more severe, such as colon cancer, they may arrange testing.

A person’s doctor will almost certainly undertake a physical examination and ask numerous questions regarding their:

  • medical history
  • medications
  • current symptoms
  • family history of bowel issues

A doctor must generally assess a person’s symptoms to diagnose IBS, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). A doctor may diagnose IBS if a person has two or more of the following symptoms in addition to stomach pain:

  • frequency of bowel movements change
  • changes in stool appearance
  • pain related to bowel movements

A doctor may also consider the length of time that symptoms have been present. According to the NIDDK, a clinician can diagnose IBS if symptoms have been present for at least 6 months and occur at least once a week for at least 3 months.

A doctor would most likely inquire about any other possible symptoms during an initial examination and inquiry. Blood in the stool, rectal bleeding, weight loss, or anemia might all be signs of a more serious condition.

If a doctor feels that another condition is causing the symptoms, extra diagnostic testing will almost certainly be ordered. They may request the following tests:

  • biopsy
  • protein and gene testing
  • ultrasound
  • colonoscopy
  • CT or CAT scan

Making a medical appointment

Pain, constipation, and other symptoms that occur on a regular basis might not always need a trip to the doctor. However, if symptoms persist or worsen, a person should consult a medical expert.

A doctor will likely examine a patient’s age, general health, family history of colon cancer, and other cancer risk factors. They may recommend a CT scan or a colonoscopy if they suspect a person’s symptoms are cancer-related.

Because the symptoms of IBS and inflammatory bowel disease (IBD) are so similar, a doctor will most likely seek to rule out IBD. IBD is an inflammatory disease that causes protracted periods of inflammation, putting a person at a higher risk of developing cancer. Colon cancer is a leading cause of death in the United States.


The symptoms of IBS and colon cancer are quite similar. However, a person with colon cancer may have unexplained weight loss, blood in their stool, or rectum hemorrhage, which are not common in IBS.

Despite having comparable symptoms, IBS does not increase the risk of colon cancer. If a person has chronic IBS symptoms, they should consult with their doctor to discover the actual cause of the symptoms and treatment options.


  • https://journals.lww.com/ajg/Abstract/2010/04000/The_Yield_of_Colonoscopy_in_Patients_With.27.aspx
  • https://www.niddk.nih.gov/health-information/digestive-diseases/irritable-bowel-syndrome/diagnosis
  • https://www.cancer.org/latest-news/signs-and-symptoms-of-colon-cancer.html
  • https://www.medicalnewstoday.com/articles/ibs-vs-colon-cancer
  • https://www.niddk.nih.gov/health-information/digestive-diseases/irritable-bowel-syndrome/symptoms-causes