Since there is no test that can be used to diagnose IBS with certainty, healthcare professionals rely on the patient’s medical history and diagnosis by exclusion – doing tests to eliminate other disorders with similar symptoms, such as celiac disease or lactose intolerance. When other disorders are ruled out, Rome IV criteria can be used to diagnose IBS.
What are Rome IV criteria?
Rome criteria are criteria used to diagnose IBS and other gastrointestinal disorders. The newest version is the Rome IV criteria updated in 2016. For the doctor to diagnose IBS using Rome IV criteria, the symptoms must have started at least six months ago. You must have had recurrent episodes of abdominal pain at least once a week for the past three months. The pain must be associated with two of the following:
- caused by bowel movements or defecation
- associated with altered stool frequency
- associated with altered stool consistency (appearance of the stool)
Diarrhea, constipation, or a mix of both are often present in patients with IBS. These symptoms are used to determine what type of IBS the patient has. There are 5 known types of IBS:
- IBS-C (IBS with constipation)
- IBS-D (IBS with diarrhea)
- IBS-M (IBS with alternating constipation and diarrhea)
- IBS-U (IBS with variable patterns)
- IBS-PI (IBS that is caused by gastrointestinal infection)
The recommended treatment of each type is different and that is why it’s important to know which type of IBS the patient has. To diagnose the IBS subtype, the Bristol Stool Form Scale is often used. It is recommended to keep track of your symptoms over a period of several months, to make the diagnosis easier. Learn more about which type of IBS you might have.