Misdiagnosed Irritable Bowel Syndrome: Is Colon Cancer Being Mistaken For IBS?

Medical researchers have begun to express concerns over an “epidemic” of irritable bowel syndrome (IBS). Between 10% and 15% of patients may have the gastrointestinal condition, which causes cramping, abdominal pain, bloating and other unpleasant symptoms. But some researchers think IBS is being over-diagnosed, with doctors missing more severe medical conditions – including colon cancer – in the process.

What Is Irritable Bowel Syndrome?

Irritable bowel syndrome is a chronic condition that requires long-term management. Although the disorder is not well-understood, researchers believe that people with IBS may have abnormal gastrointestinal contractions – either too strong or too weak – that lead to painful symptoms.

More than a single medical condition, with a precise cause, irritable bowel syndrome is better thought of as a collection of symptoms.

The signs and symptoms of irritable bowel syndrome, however, can vary widely, according to the Mayo Clinic:

  • abdominal pain
  • cramping
  • bloating
  • excessive gas
  • mucus in stool
  • diarrhea and constipation, often alternating

Irritable bowel syndrome is around twice as common in women as men.

Some studies suggest that genetics play a role in IBS, while others contradict that claim. In a portion of cases, the disease will be attributed to neurological disorders, with poorly-timed brain signals causing the body to overreact to normal digestive processes. Lifestyle factors like chronic stress and poor diets are also believed to contribute to the gastrointestinal disorder.

Does IBS Cause Cancer?

No. There is no credible link between irritable bowel syndrome and an increased risk for colorectal cancers. There is, however, an associated problem. Physicians may be misdiagnosing many patients – mistaking cases of colon cancer for irritable bowel syndrome.

IBS diagnoses have increased in recent years. Doctors are now recognizing the condition as an extremely common ailment among patients, young and old. At any rate, irritable bowel syndrome is far more common than colon cancer – but the two conditions, one benign and the other malignant – can cause strikingly similar symptoms.

To complicate the picture, irritable bowel syndrome can be easily mistaken for “inflammatory” bowel diseases – like ulcerative colitis – which do increase the risk for colon cancer. In other words, a misdiagnosed case of ulcerative colitis or Crohn’s disease, treatable if diagnosed properly, could lead to colorectal cancer in the long-term.

Colon Cancer Or IBS?

Misdiagnoses of colon cancer are surprisingly common, the Daily Mail reports. As we’ve seen, the symptoms of irritable bowel syndrome are easily mistaken for the symptoms of irritable bowel syndrome.

There are, however, red flags that could indicate a more serious – and potentially malignant – condition:

  • Inexplicable weight loss
  • Rectal bleeding – Only around 20% of patients with irritable bowel syndrome experience rectal bleeding. Rectal bleeding is far more common in patients with colon cancer, especially darker blood mixed in with stool.
  • Constant bloating – While most patients with irritable bowel syndrome will experience bloating, the symptom usually fluctuates over time in IBS – stronger in the morning and waning towards the night. Bloating in colon cancer is usually constant, both over time and in its severity.
  • Pain that doesn’t move – The pain caused by irritable bowel syndrome is often mobile, moving from one part of the intestine to another. In more serious conditions, pain usually stays in one place, potentially because it’s being caused by a stationary tumor.
  • Ineffective treatments – IBS is a chronic condition, but it’s one we know how to treat fairly well. Medications, like the anti-spasmodic Buscopan, and switching to a low-fiber diet can help many people with irritable bowel syndrome. But if your symptoms aren’t relieved by these treatments, it can be a sign that they aren’t being caused by irritable bowel syndrome.

We don’t have an adequate understanding of how often irritable bowel syndrome is misdiagnosed as colon cancer. There just aren’t statistics on the issue. But Tariq Ismail, a colorectal surgeon in Birmingham, England says that up to 20% of colon cancer patients may be told they have IBS before receiving a correct diagnosis. Ismail was interviewed by the Daily Mail in 2012.

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