What's a Food Allergy?
How to Get Started
Food Allergy Testing
About Irritable Bowel
Newsletter Archive
Frequent Questions
Dietary Supplements
Supplements Store
Site Map
Link to this Site
Meet Dr. Wangen

You will be redirected to the Digestion Basics page at http://www.ibstreatmentcenter.com/2.htm in 5 seconds. If you are not redirected, please click here.

Diagnosis of
Irritable Bowel Syndrome (IBS)

For Dr. Wangen's website completely devoted to Irritable Bowel Syndrome, go to www.IBSTreatmentCenter.com.

This page describes how IBS is diagnosed.

Diagnostic Criteria for Irritable Bowel

At least 12 weeks or more, which need not be consecutive, in the preceding 12 months of abdominal discomfort or pain that has two of the following three features:

  • Relief by defecation
  • Onset associated with a change in the frequency of stool
  • Onset associated with a change in the form (appearance of stool).
Symptoms that cumulatively support the diagnosis of IBS:
  • Abnormal stool frequency (> 3 bowel movements per day or < 3 bowel movement per week)
  • Abnormal stool form (lumpy/hard or loose/watery)
  • Abnormal stool passage (straining, urgency, or feeling of incomplete evacuation)
  • Passage of mucous
  • Bloating or a feeling of abdominal distention.

Clinical Features Supporting the Diagnosis of Irritable Bowel Syndrome

  • A long history of IBS that comes and goes
  • Symptoms are exacerbated by stressful life events
  • Variability in symptoms
  • Symptoms that are made worse by eating.

Clinical & Lab Features Suggesting Disease other than Irritable Bowel Syndrome

  • Onset in old age
  • Course of condition is progressively worse over time
  • Fever
  • Weight loss
  • Rectal bleeding from causes other than constipation, anal fissures and hemorrhoids
  • Fat in the stool
  • Dehydration.
The symptoms of IBS can also be found in patients with inflammatory bowel disease, diverticular disease, solitary rectal ulcer syndrome, and many other conditions. However, the diagnosis of IBS is based on the absence of organic disease such as that found in rectal bleeding and weight loss, as well as the chronic history of symptoms, the relationship between the exacerbations of symptoms and life events, the variability of symptoms, the presence of anxiety and depression, and distress over the symptoms.


Other Diagnostic Considerations

The findings on physical exam, sigmoidoscopy and colonoscopy are normal in IBS. Other issues to rule out include the following:

  • A change in dietary habits or therapeutic regimens may trigger the development of symptoms of IBS or cause symptoms suggestive of IBS. Particular attention should be given to an abnormally low or excessive intake of dietary fiber or excess ingestion of poorly absorbed sugars, such as fructose or sorbitol, or stimulants, such as coffee.

  • Diarrhea can be caused by these medications:
    • Angiotensin converting enzyme (ACE) inhibitors
    • beta blockers
    • antibiotics
    • chemotherapeutic agents
    • proton pump inhibitors (Prevacid, Prilosec, Aciphex, and Nexium)
    • nonsteroidal anti-inflammatory drugs (acetaminophen, Tylenol, aspirin).

  • Constipation can be caused by these medications:
    • opiate analgesics
    • calcium channel blockers
    • antidepressants with anticholinergic effects.

Click on the links below for more information.

Information on Irritable Bowel Syndrome

Irritable Bowel Syndrome Symptoms

How Irritable Bowel Syndrome Develops

Causes of Irritable Bowel Syndrome

Irritable Bowel Syndrome Treatment

IBS Diet

Dr. Stephen Wangen
IBS Treatment Center and Center for Food Allergies
Email: info@CenterForFoodAllergies.com
11300 Roosevelt Way NE Suite 100 Seattle, WA 98125 • 206-264-1111

Food Allergies • Food Intolerance • Gluten Intolerance • Wheat Allergy
Milk Allergy • Peanut Allergy • Lactose Intolerance • Allergy Testing
Elimination Diet • Allergy Products • Supplements