Definition
- Episodic or continuous abdominal pain lasting for a period of at least 2 months.
- Affects approximately 10% of school-aged children.
- Often referred to as functional abdominal pain when no underlying organic cause is identified.
Diagnostic Features Of Functional Recurrent Abdominal Pain
Clinical Presentation
- Diagnosis relies on symptom-based Rome IV criteria.
- Requires absence of organic, inflammatory, anatomic, metabolic, or neoplastic processes explaining symptoms.
- Pathophysiology frequently linked to visceral hyperalgesia and disordered brain-gut communication.
Rome IV Classification Subtypes
| Subtype | Diagnostic Criteria |
|---|---|
| Functional abdominal pain - not otherwise specified | Episodic or continuous periumbilical pain occurring $\ge$ 4 times/month for >2 months; insufficient criteria for other functional disorders. |
| Irritable bowel syndrome | Abdominal pain $\ge$ 4 days/month associated with defecation, change in stool frequency, or change in stool form. |
| Functional dyspepsia | Postprandial fullness, early satiety, epigastric pain/burning not relieved by defecation. |
| Abdominal migraine | Paroxysmal intense periumbilical/midline pain >1 hour; associated with anorexia, nausea, vomiting, headache, photophobia, pallor. |
Absence Of Alarm (Red Flag) Signs
- Functional diagnosis requires rigorous exclusion of alarm signs.
- Involuntary weight loss, deceleration of linear growth, delayed puberty.
- Gastrointestinal blood loss (hematochezia, melena, occult blood).
- Chronic severe or nocturnal diarrhea.
- Persistent right upper or right lower quadrant pain.
- Unexplained fever, arthritis, spinal tenderness, perianal disease.
- Family history of inflammatory bowel disease, celiac disease, or peptic ulcer disease.
- Pain awakening child from sleep.
Investigation Plan
- Avoid extensive invasive testing if typical functional features exist without red flags.
Baseline Screening
| Investigation | Rationale |
|---|---|
| Complete blood count | Exclude anemia, underlying infection. |
| Inflammatory markers (ESR, CRP) | Rule out systemic inflammation or inflammatory bowel disease. |
| Comprehensive metabolic panel | Assess hepatic and renal function. |
| Celiac serology | Measure tissue transglutaminase IgA, total serum IgA. |
| Stool analysis | Check for occult blood, ova/parasites, Giardia. |
| Fecal calprotectin | Differentiate functional pain from inflammatory bowel disease. |
| Urinalysis | Exclude urinary tract infection. |
Advanced Testing
- Reserved exclusively for cases exhibiting alarm signs or refractory symptoms.
- Abdominal ultrasonography.
- Esophagogastroduodenoscopy or ileocolonoscopy.
Management Protocol
- Implement individualized biopsychosocial approach.
Behavioral And Psychosocial Interventions
- Validate patient symptoms; pain is real, not imagined.
- Educate parents and child regarding brain-gut axis and visceral hyperalgesia concepts.
- Reassure regarding benign, non-progressive nature of ailment.
- Normalize lifestyle; discourage school absenteeism; minimize excessive parental attention to pain behavior.
- Implement cognitive behavioral therapy, gut-directed hypnotherapy, or guided imagery to enhance coping mechanisms.
Dietary Modifications
- Provide well-balanced, nutritious diet with adequate fiber.
- Restrict excessive intake of carbonated beverages, refined foods, and fruit juices (sorbitol/fructose).
- Consider temporary low-FODMAP diet if pain associates heavily with bloating.
Pharmacotherapy
- Avoid unnecessary medication; utilize empiric therapies for refractory symptoms affecting quality of life.
- Antispasmodics: Peppermint oil or hyoscyamine for irritable bowel syndrome.
- Probiotics: Lactobacillus rhamnosus GG administration may reduce abdominal pain frequency and intensity.
- Neuromodulators: Amitriptyline or selective serotonin reuptake inhibitors (SSRIs) indicated for severe, disabling pain with comorbid anxiety or depression.
- Cyproheptadine: May improve gastric accommodation in functional dyspepsia.