Irritable Bowel Syndrome Ibs Diagnosis

The First Step

Because IBS is a disorder that relates to intestinal function, diagnosis requires a somewhat different approach. A routine starting point, therefore, involves analyzing the patient ‘s medical history and conducting a thorough physical examination. Subsequent diagnosis is based upon identifying a pattern of symptoms that corresponds to established IBS criteria.

The Next Step in IBS Diagnosis

Depending upon the symptoms manifested by the patient and other factors, such as age and general state of health, further diagnostic testing may be required, primarily to eliminate the possibility of unrelated medical conditions.

In certain instances, such investigations are essential to exclude the presence of other life-threatening disorders that superficially exhibit symptoms similar to IBS.

Infection, inflammation or growth abnormalities are not associated with irritable bowel syndrome. If the results of these tests prove negative, further testing is in order.

Diagnostic techniques to eliminate the possibility of other gastrointestinal conditions may include:

  • blood tests
  • stool tests
  • bacterial cultures
  • x-rays
  • endoscopy
  • colonoscopy
  • CAT scan.

With younger patients, the diagnosis of IBS tends to be a fairly straightforward procedure. After a few simple investigations, the doctor is usually able to diagnose conclusively and recommend appropriate treatment.

Older patients are more likely to require further investigation to exclude other gastrointestinal conditions and bowel disorders. This may include a medical imaging tests such as colonoscopy, endoscopy, CAT scan and radiology, as well as a range of laboratory tests. In addition, a patient ‘s response to initial treatment may be used to help with diagnosis. For instance, non-typical symptoms of IBS such as blood in the stool or weight loss may indicate that immediate, further investigations are required.

Recent Developments in the Diagnosis of Irritable Bowel Syndrome

Over the past two decades, a greater understanding of the typical irritable bowel symptoms has enabled the medical profession to diagnose IBS accurately without the intervention of techniques that may, in themselves, cause further complications and inconvenience for the patient.

Extensive diagnostic imaging tests are now more likely to be applied only as a last resort, when all other methods have failed to produce a diagnosis.

According to George F. Longstreth, M.D., Chief of Gastroenterology of Kaiser Permanente San Diego and Clinical Professor of Medicine at University of California, San Diego, medical opinion has shifted in recent years regarding the diagnosis of IBS. Whereas previously the emphasis was on “diagnosis by exclusion, ” the preferred approach today is less intrusive.


Beers, M.H.,