In June 2016, Rome IV, a comprehensive document that took 6 years to develop, was published to update the ROME III document published in 2006. It is the result of the collaboration of 117 experts from 23 countries. Rome IV includes criteria for diagnosing all functional GI disorders.

The New Rome IV criteria for IBS reflect advances in recent scientific research and clinical studies and offers several advancements in the description and diagnosis of bowel disorders.

ROME IV Criteria for Functional Bowel Disorders

‘Functional GI Disorders’ involve the gut–brain interaction. Under this umbrella term, are multiple disorders, all classified by GI symptoms that are related to any combination of the following:

• Disturbances in movement of food and food waste through the GI tract (‘motility disorder’).
• Increased subjective experience of pain in visceral organs (‘visceral hypersensitivity’).
• Alterations in gut immunity (‘altered mucosal and immune function’).
• Alterations to the commensal bacteria in the gut (‘altered gut microbiota’.
• Alterations in the messages between the brain and the gut (‘altered central nervous system processing’).

This inclusion criteria for Function GI Disorder, implies that there are multidirectional interactions between bodily processes, the brain, and the gut. Rome IV places a strong emphasis on a biopsychosocial approach in the treatment of Functional GI disorders.

Recommended Approach to Consider

• Early Life Influences: Genetic Factors, Cultural Norms, Environmental factors
• Psychosocial factors: stress, personality, psychological state, coping, social support.
• Physiology: motility, sensation, immune function, microflora, food, diet.

Diagnosis of IBS with Rome IV Criteria

Recurrent abdominal pain, on average, at least 1 day/week in the last 3 months, associated with two or more of the following:

• Related to defecation.
• Associated with a change in frequency of stool.
• Associated with a change in form (appearance) of stool.
• Criteria fulfilled for the last 3 months with symptom onset at least 6 months before diagnosis.

IBS Subtypes

The four main subtypes of IBS are mentioned below:

• BS-C (predominant constipation),
• IBS-D (predominant diarrhea), and
• IBS-M (IBS with mixed bowel habits), as shown in Table 2.2
• People whose symptoms do not fit into any category are considered to have IBS unclassified.