The Rome III criteria system was developed to classify the functional gastrointestinal disorders (FGDs) based on their clinical symptoms. Since by definition, evidence of FGDs does not show up through standard diagnostic testing, the Rome criteria are designed to help healthcare providers to make diagnoses of FGDs with confidence. The Rome criteria also allow for standardized diagnostic criteria to be used in the process of research trials.

The Rome criteria are developed through a collaboration of researchers, healthcare providers and other health professionals from around the world. The Rome III criteria reflect the third revision of the FGD diagnostic criteria and were published in 2006. Another revision, Rome IV, is due to be published in the Spring of 2016.

Types of Functional Gastrointestinal Disorders

Each FGD disorder has its own set of criteria. The following are the major categories of FGDs according to the Rome III criteria:

  • Functional Esophageal Disorders
  • Functional Gastroduodenal Disorders
  • Functional Bowel Disorders
  • Functional Abdominal Pain Syndrome
  • Functional Gallbladder and Sphincter of Oddi Disorders
  • Functional Anorectal Disorders
  • Childhood Functional GI Disorders: Infant/Toddler
  • Childhood Functional GI Disorders: Child/Adolescent

The Rome III Criteria for IBS

The criteria for a diagnosis of irritable bowel syndrome (IBS} require that a person be experiencing chronic abdominal pain or discomfort at least three days over the course of the last three months, with an onset of symptoms at least six months prior. These symptoms must also show:

  • Pain symptoms are lessened with a bowel movement
  • Symptom onset is related to a change in the frequency of stool
  • Symptom onset is related to a change in the appearance of stool

Although the Rome III criteria are followed strictly in clinical research trials, in the real world, healthcare providers often give a diagnosis of IBS to anyone who is experiencing bowel symptoms without any visible inflammation or other signs of disease showing up through standard digestive testing.

Other Functional Bowel Disorders

The following are other types of functional bowel disorders. A person would be diagnosed with one of these other disorders when they don’t fit the diagnostic criteria for IBS (or any other disease or FGD). Often these other disorders are differentiated from IBS due to the lack of pain as a symptom.

Functional bloating: Chronic feelings of bloating and/or visible distension. The symptom must have occurred on at least three days over the last three months and at least six months prior to diagnosis.

Functional diarrhea: The experience of loose or watery stools without pain occurring in at least 75% of bowel movements for at least three months over the last six months.

Functional constipation: Symptoms must include at least two of the following and have been experienced for at least three months over the past six months.

  • Straining (at least 25% of the time)
  • Hard stools at least 25% of the time
  • Feeling of incomplete evacuation (at least 25% of the time)
  • Sensation of blockage or obstruction in the anus or rectum area
  • Manual efforts to enable the passage of stool at least 25% of the time (e.g. digital evacuation)
  • Less than three bowel movements per week
  • Rare occurrence of loose stools without the use of a laxative

Rome III in the Real World

As designed, the Rome III criteria provide a strong basis for identifying patients for research studies. However, healthcare providers in their clinical practice don’t always focus on such exacting criteria when offering functional diagnoses to their patients. Thus, there is no need to be overly concerned if you receive a diagnosis that doesn’t completely conform to the criteria. But if you still have any questions about your diagnosis, ask your healthcare provider for clarification.