Reaching an IBS Diagnosis
Irritable Bowel Syndrome is a widespread disorder, but it can also be one of the most challenging to diagnose. Although the physical symptoms are very uncomfortable, often uncontrollable and possibly severe enough to warrant psychiatric treatment, there is presently no clinical test to determine if IBS is truly to blame for this enormous impact on daily life.
An IBS diagnosis rests on the process of elimination, but advances in research and creative diagnostic approaches can minimize the time, money and effort that it takes to reach a conclusion and start treatment.
Diagnostic Approaches for IBS
The primary symptoms of IBS are easy to spot: bloating, excessive gas, diarrhea, constipation, regular changes in bathroom habits and abdominal pain. The key is to ensure these signs do in fact point to IBS and not another disorder, using a few investigative tools:
- Elimination diet. Once your doctor has ruled out a lactose or gluten intolerance, begin by eliminating suspect foods from your daily diet for two weeks. Although virtually any foods could trigger IBS symptoms, dairy, soy, wheat and certain chemical preservatives are common culprits. When the two weeks are up, begin slowly reintroducing foods one at a time, and monitor your physical reactions.
- Diagnostic testing for other illnesses. IBS is generally diagnosed based on reported symptoms, but it can be helpful to rule out similar diseases first. Blood tests for celiac disease, stool analysis to check for infection or parasites, or a colonoscopy to investigate physical abnormalities in the bowel can be performed before treatment for IBS begins.
- Blood test for biomarkers. A recently developed blood test for antibodies associated with IBS and IBD has returned promising results, and researchers are hopeful that this simple test will avoid misdiagnoses and unnecessary suffering for IBS patients in the future.
Since there is no laboratory test for the disorder, experts have developed a clear and thorough list of symptom-based criteria to support an accurate diagnosis. The Rome criteria is still considered one of the most important diagnostic tools for IBS.
The first Rome criteria for IBS diagnosis is continuous or recurring abdominal pain at least 3 days per month over the last 3 months. This pain may be relieved with a bowel movement, or associated with a change in the stool consistency or frequency. Secondly, two of the following symptoms must be present at least 25% of the time:
- Mucus in the stool
- Bloating or a distended stomach
- Straining or a sense of urgency in bowel movements
- Noticeable difference in the stool consistency
Different patients can experience IBS symptoms differently, so there are also subcategories in IBS diagnosis based on whether diarrhea or constipation are predominant, or how they alternate.
Other Considerations for an Accurate Diagnosis
While a process of elimination and a close evaluation of symptoms can often lead to a firm IBS diagnosis, certain circumstances will call for more thorough testing. For instance, a young adult with chronic and fluctuating gastrointestinal symptoms will be relatively easy to diagnose, but a sudden onset of symptoms in an adult over age 55 might arouse suspicion. Therefore, your age, medical history, severity of symptoms and risk factors for other diseases should be considered before your doctor can make a confident diagnosis.