Diagnostic Criteria for Functional Abdominal Pain

Introduction to Functional Gastrointestinal Disorders

The Rome Foundation reorganized functional gastrointestinal disorders into "disorders of gut-brain interaction", recognizing the complex interplay of biological, psychological, and social factors, with abdominal pain being a cardinal symptom in several of these disorders 1

IBS is the primary disorder that features abdominal pain as a central characteristic, with recurrent abdominal pain, on average, at least 1 day per week in the last 3 months, associated with two or more of the following: related to defecation, associated with a change in stool frequency, or associated with a change in stool form 2, 1, 3
The American Gastroenterological Association recommends that the diagnostic criteria for IBS include at least 1 day of abdominal pain per week, which is a change from the previous Rome 3 criteria of 3 days per month, with the goal of improving diagnostic accuracy 2, 6

Functional dyspepsia also features abdominal pain, localized to the epigastrium, with one or more of the following uncomfortable symptoms (sufficiently severe to impact daily activities): epigastric pain, epigastric burning, postprandial fullness, or early satiation 7, 4
The Rome Foundation suggests that the diagnostic criteria for functional dyspepsia include symptoms that have been present for at least 6 months, with an onset of at least 6 months before diagnosis, and that the symptoms are not better explained by another medical condition 7, 4, 5

In IBS, abdominal pain is generally located in the lower abdomen, related to defecation, and associated with changes in bowel habits, but not necessarily related to meals 1, 3
In functional dyspepsia, abdominal pain is localized to the epigastrium, may occur during fasting or be precipitated/exacerbated by meals, and is not related to the need to defecate 8

Up to 50% of patients with functional dyspepsia have overlap with IBS, with the patient reporting two different types of abdominal pain: one related and one not related to defecation 8

Do not confuse functional dyspepsia with gastroesophageal reflux disease (GERD), as the burning that starts in the epigastrium but radiates to the chest suggests GERD, not functional dyspepsia 8
The Rome Foundation suggests that relaxing the frequency of pain to 3 days per month (instead of 1 day per week) may improve diagnostic performance without losing specificity, although this is not part of the official Rome 4 criteria 7, 4