Rome V Pediatric Lower DGBI: Gastroenterology | May 2026

Rome V reframes pediatric lower gastrointestinal disorders of gut–brain interaction (DGBI) around symptom clusters and anatomic domains rather than age-based groupings, a clinically important shift that better reflects how these disorders present in practice across childhood and adolescence. The lower DGBI spectrum is now organized into abdominal pain disorders, defecation and anorectal disorders, and discomfort disorders, allowing clinicians to approach symptoms according to dominant physiology rather than rigid age cutoffs. This revision also formally recognizes several entities that pediatric gastroenterologists have long encountered but previously lacked standardized pediatric definitions for, including biliary pain syndrome, centrally mediated abdominal pain syndrome, proctalgia fugax, and functional abdominal bloating. The practical consequence is earlier recognition, reduced diagnostic ambiguity, and less exposure to inappropriate testing or empiric treatment in children with otherwise poorly classified symptoms.

Irritable Bowel Syndrome: Pain Becomes the Diagnostic Anchor

Rome V sharpens the pediatric definition of irritable bowel syndrome (IBS) by making abdominal pain, rather than bowel habit disturbance alone, the dominant diagnostic feature. This is a clinically meaningful departure from Rome IV, particularly in children with constipation. Rather than requiring a trial of constipation treatment to separate IBS-C from functional constipation, Rome V now distinguishes the two by symptom dominance: when abdominal pain is the primary complaint and is linked to stooling, IBS is favored; when bowel dysfunction predominates and pain is secondary, functional constipation is more appropriate. This change better reflects real-world pediatric presentations and avoids prolonged diagnostic uncertainty. The criteria also now exclude pain occurring solely during menses, reducing misclassification of dysmenorrhea as IBS in adolescent girls.

Mechanistically, pediatric IBS is increasingly understood as a disorder of altered gut–brain signaling rather than a purely motility-based condition. Rome V reinforces the relevance of early-life programming, including antibiotic exposure, neonatal interventions, early infection, and adverse psychosocial experiences, all of which may prime visceral hypersensitivity and dysregulated central pain processing. Children with IBS show lower rectal sensory thresholds, increased intestinal permeability, low-grade mucosal immune activation, altered microbial composition, and food-triggered symptom amplification. These mechanistic insights are clinically relevant because they support individualized therapy rather than symptom suppression alone. In practice, evaluation should be directed by phenotype. IBS-D warrants screening for celiac disease, inflammatory markers, and selective evaluation for bile acid malabsorption or carbohydrate malabsorption. IBS-C requires differentiation from primary defecatory disorders. The strongest therapeutic evidence remains for gut–brain therapies, particularly cognitive behavioral therapy and hypnotherapy, both of which should be considered first-line in children with clinically significant IBS. Adjunctive therapies such as percutaneous electrical nerve field stimulation, selected probiotics, enteric-coated peppermint oil, psyllium, and subtype-specific bowel therapies can be layered according to phenotype and severity.

Abdominal Pain Syndrome–Not Otherwise Specified: The Intermittent Pain Phenotype

Rome V replaces functional abdominal pain–not otherwise specified with abdominal pain syndrome–not otherwise specified (APS-NOS), clarifying this as an intermittent pain disorder that does not meet criteria for IBS, functional dyspepsia, abdominal migraine, or biliary pain syndrome. The distinction is clinically useful because it captures children with recurrent abdominal pain who often undergo extensive evaluation but do not fit a better-defined Rome phenotype. Rome V also explicitly distinguishes APS-NOS from centrally mediated abdominal pain syndrome by emphasizing intermittent rather than continuous pain. Pain occurring exclusively with meals, bowel movements, or menses should prompt alternative diagnoses.

From a mechanistic standpoint, APS-NOS likely shares many pathophysiologic pathways with IBS, including altered visceral perception, dysregulated autonomic signaling, and psychosocial amplification, but without a defining stool pattern or meal association. In practice, evaluation is guided by exclusion of inflammatory, structural, and celiac pathology when clinically indicated, followed by reassurance and early symptom-directed management. The therapeutic approach parallels IBS, with strongest evidence for CBT, hypnotherapy, and neuromodulation strategies rather than escalating diagnostic testing.

Biliary Pain Syndrome: A New Pediatric Rome Diagnosis With Major Clinical Implications

Biliary pain syndrome is one of the most important additions in Rome V because it introduces a formal pediatric diagnostic framework for children previously labeled with “biliary dyskinesia,” a term widely used but poorly standardized. Rome V intentionally moves away from the surgical shorthand of biliary dyskinesia and instead defines a symptom-based DGBI characterized by episodic right upper quadrant pain, often postprandial, severe enough to prompt acute evaluation, in the absence of gallstones or structural biliary disease. This is highly relevant in pediatric practice, where increasing rates of cholecystectomy have often been driven by nonspecific symptoms and unreliable gallbladder ejection fraction studies.

The Rome V position is clinically decisive: gallbladder ejection fraction should not be used diagnostically in isolation, and cholecystectomy should not be reflexive. Evaluation should prioritize exclusion of stones, biliary tract pathology, pancreatobiliary structural disease, and biochemical abnormalities through ultrasound, selective MRCP, and liver-pancreatic biochemistry. In many children, conservative management may outperform surgery over time, and spontaneous improvement is well documented. Rome V therefore shifts pediatric practice toward diagnostic restraint and away from surgery-first decision making. This is likely to reduce unnecessary cholecystectomy in adolescents with functional pain syndromes.

Abdominal Migraine: Episodic Neuroenteric Pain, Not Functional Dyspepsia

Rome V retains abdominal migraine unchanged, reflecting continued confidence in its construct as a stereotyped episodic pain syndrome within the migraine spectrum. This remains an important diagnosis in children with severe recurrent periumbilical or diffuse pain accompanied by pallor, nausea, vomiting, headache, or photophobia. The practical importance lies in recognizing abdominal migraine as a neuroenteric episodic disorder rather than misclassifying it as refractory dyspepsia or recurrent unexplained abdominal pain.

The mechanistic model is increasingly aligned with cyclic vomiting syndrome and migraine biology, involving neuronal hyperexcitability, altered gastric motor function, and possibly mitochondrial dysfunction. Clinically, this diagnosis matters because it reframes treatment away from repeated gastrointestinal investigation and toward trigger identification, migraine-style prophylaxis, and selected abortive therapy. In children with frequent disabling attacks, cyproheptadine, propranolol, pizotifen, and flunarizine remain practical preventive options, while severe attacks may respond to triptan-based or antiemetic rescue strategies.

Centrally Mediated Abdominal Pain Syndrome: Recognizing the Continuous Pain Phenotype

Centrally mediated abdominal pain syndrome (CAPS) is another major addition in Rome V and fills a longstanding gap in pediatric DGBI classification. CAPS identifies children with continuous abdominal pain and functional impairment in whom central pain amplification, rather than peripheral gastrointestinal dysfunction, is likely the dominant driver. This diagnosis is clinically important because it validates a phenotype that is often over-investigated, mislabeled, or treated as refractory IBS despite a distinct pain biology.

The practical implication is that continuous pain should prompt a different clinical strategy than intermittent pain syndromes. CAPS requires a multidisciplinary model centered on functional restoration, pain neuroscience education, school reintegration, and targeted brain–gut therapies. Psychological assessment is essential, not to psychologize symptoms, but to identify pain-specific cognitions, maladaptive coping, family responses, and disability drivers. Neuromodulators, including tricyclics, SSRIs, mirtazapine, gabapentinoids, and behavioral therapies, are mechanistically aligned with CAPS and should be prioritized over repeated diagnostic escalation.

Functional Constipation: Clarified Criteria, Stronger Clinical Precision

Rome V preserves functional constipation as a distinct entity but improves diagnostic precision by clarifying stool retention behaviors, stool form descriptors, and symptom frequency. Most importantly, Rome V explicitly separates constipation from IBS by emphasizing that when abdominal pain is the dominant symptom and improves with defecation, IBS should be favored. This distinction is highly relevant in pediatric practice, where constipation and pain frequently overlap and are often conflated.

Rome V continues to support a clinically grounded approach: diagnosis is usually made from history and examination, not imaging. Routine abdominal radiographs remain low-yield and should not be used reflexively. Treatment remains structured and pragmatic, beginning with education, disimpaction, maintenance laxative therapy, toileting behavior, and escalation to stimulant laxatives or newer agents such as linaclotide in selected refractory cases. The guideline also reinforces that refractory constipation is a separate management problem requiring escalation to motility-focused interventions rather than indefinite cycling of standard laxatives.

Functional Diarrhea and Functional Abdominal Bloating: Symptom-Led, Mechanism-Aware Diagnosis

Rome V broadens functional diarrhea across the pediatric age spectrum and provides a more clinically useful distinction from IBS-D by emphasizing that diarrhea without pain is functional diarrhea, whereas pain-predominant diarrhea is IBS-D. This distinction is especially useful in adolescents, where overlap is common and symptom labeling has therapeutic consequences. Evaluation should remain conservative but targeted, focusing on malabsorption, inflammation, and dietary contributors only when clinically justified.

Functional abdominal bloating is newly recognized and clinically valuable because it legitimizes a symptom complex commonly encountered in practice but often poorly classified. Rome V acknowledges that bloating and visible distension may reflect distinct mechanisms including gas handling abnormalities, carbohydrate fermentation, abdominophrenic dyssynergia, pelvic floor dysfunction, visceral hypersensitivity, and behavioral stool retention. This is particularly relevant in adolescents with distension out of proportion to stool burden or gas volume. Management should therefore move beyond empiric simethicone and include attention to fermentation load, posture, evacuation mechanics, and in selected cases, biofeedback-directed correction of abdominophrenic discoordination.

Infant Distress Syndrome: A More Accurate Framework Than “Infantile Colic”

Rome V replaces “infantile colic” with infant distress syndrome (IDS), a clinically and conceptually important change. The term “colic” implied pain of colonic origin without evidence; IDS instead frames excessive crying as a multifactorial disorder of gut–brain regulation in early infancy. This is more biologically plausible and clinically useful. Rome V also removes the rigid 3-hour crying threshold from routine clinical diagnosis, recognizing that caregiver burden, not just crying duration, determines clinical significance.

This change has practical value in pediatric care because it validates distressed infants who previously fell below arbitrary research cutoffs but still caused major caregiver dysfunction. Evaluation remains focused on exclusion of red flags and caregiver assessment rather than indiscriminate investigation. IDS is best managed through reassurance, caregiver support, normalization of symptom trajectory, and selective use of low-risk interventions such as Limos lactobacillus reuteri or cow’s milk elimination in selected infants. The shift from “colic” to IDS is not merely semantic; it reframes the condition from presumed intestinal pain to early-life dysregulation of gut–brain function and caregiver-infant interaction.