If you have IBS, you may be fearing eventual cancer, wondering if irritable bowel syndrome can lead to or increase cancer risk.
However, fear no more. A report in the American Journal of Gastroenterology (2010) has reassuring news.
“Patients and doctors get nervous about the symptoms of irritable bowel syndrome (IBS),” says William D. Chey, MD, in the report, and lead study author, and professor of Internal Medicine at the University of Michigan Medical School.
This is especially true because the symptoms of IBS are nearly identical — to the symptoms of colon cancer.
However, this new research demonstrates that having irritable bowel syndrome is not a marker for future colon cancer, and does not increase the risk for colon cancer or even polyps, the precursors to this disease.
The study investigated colonoscopy results of people with IBS.
Symptoms of IBS can be scary, and include alternating bouts of diarrhea and constipation — which can occur with colon cancer as well.
Abdominal pain is another classic feature of both irritable bowel syndrome and colon cancer.
Ten to 20 percent of the U.S. has IBS; this disorder is diagnosed after other possible causes of the symptoms have been ruled out.
Chey’s research indicates that colonoscopies are not necessary for IBS patients who don’t present with “alarming” symptoms such as unexplained weight loss or blood in the stools, or who don’t have family histories of colon cancer.
He believes that doctors use colonoscopies, which are expensive and invasive, too much.
But Chey does explain: “…patients over the age of 50 years or who have alarm features should undergo colonoscopy to screen for polyps and colon cancer.”
The research also revealed that 2.5 percent of irritable bowel patients over age 35 has microscopic colitis.
This rare condition can mimic IBS, but a differentiating feature is that in microscopic colitis, there is no constipation.
Tissue samples from the large colon are taken during a colonoscopy and examined under a microscope for the tell-tale signs of microscopic colitis, whose hallmark symptom is diarrhea, particularly watery. A change in stool appearance is also a feature.
Like IBS, microscopic colitis has not been shown to increase the risk of colon cancer, or in any way be a marker for this disease.
If you have unexplained diarrhea or a change in bowel habits lasting longer than two weeks, consult with a gastroenterologist to rule out colon cancer.