What is the treatment approach for functional abdominal pain in a patient without significant medical history, such as HIV?

Treatment of Functional Abdominal Pain in a Normal Person

Functional abdominal pain requires a multimodal approach combining patient education about pain neurophysiology, cognitive behavioral therapy as first-line treatment, and antispasmodic medications (dicyclomine 40 mg four times daily) for symptomatic relief, with tricyclic antidepressants or gabapentinoids reserved for refractory cases. 1, 2, 3

Initial Assessment and Diagnostic Approach

Screening and Symptom Characterization

• Screen with two questions: "How much bodily pain have you had during the last week?" and "Do you have bodily pain that has lasted for more than 3 months?" 1
• Document pain location, quality (cramping vs. constant), severity using a pain scale, temporal patterns, and whether pain is associated with bowel habit changes or eating 1, 4
• Use the ultra-brief PEG tool (Pain intensity, interference with Enjoyment of life, interference with General activity) for rapid assessment in busy clinical settings 5, 1
• Functional abdominal pain syndrome is defined as constant or nearly constant abdominal pain present for at least 6 months with loss of daily functioning, differentiated from irritable bowel syndrome by non-association with changes in bowel habit or eating 6

Physical Examination and Red Flags

• Perform focused physical examination looking specifically for: peritoneal signs, palpable masses, organomegaly, and localized tenderness that suggests structural disease 4
• Recognize alarm signals requiring immediate workup: unintentional weight loss, blood in stool, fever, nocturnal symptoms, family history of gastrointestinal malignancy, age >50 with new-onset symptoms 4
• If alarm features are present, pursue diagnostic testing (blood work, imaging, endoscopy) before labeling as functional 7

Psychosocial Evaluation

• Screen for depression with two questions: "During the past 2 weeks have you often been bothered by feeling down, depressed, or hopeless?" and "During the past 2 weeks have you been bothered by little interest or pleasure in doing things?" 5, 1
• If positive response to either question, use PHQ-9 screening tool; scores ≥10 require psychiatric follow-up 5
• Assess modifiable psychosocial factors: self-esteem and coping skills, recent major loss or grief, history of violence or lack of safety in home, mood disorders 5, 1

Core Treatment Framework

Patient Education as Foundation

• Explain that functional abdominal pain results from amplified central perception of normal visceral input rather than ongoing tissue damage 6, 8
• Educate on pain neurophysiology: the pain system involves peripheral receptors, spinal cord processing, and brain interpretation within a biopsychosocial context, meaning the same signal produces different pain experiences in different individuals 5
• Set realistic expectations: the goal is functional restoration and improved quality of life, not complete pain elimination 5, 1
• This educational foundation provides the rationale for introducing non-pharmacological interventions and helps patients understand why psychological treatments are effective 3

First-Line Non-Pharmacological Interventions

• Cognitive Behavioral Therapy (CBT) is strongly recommended as first-line treatment for functional abdominal pain, addressing pain catastrophizing, developing coping strategies, and reducing pain-related disability 1, 9, 3
• Physical therapy with focus on relaxation techniques and graded activity is recommended to improve function 1, 3
• Hypnotherapy is recommended specifically for functional gastrointestinal pain 1, 3

Pharmacological Treatment Algorithm

First-Line Pharmacotherapy: Antispasmodics

• Dicyclomine 40 mg four times daily (160 mg total daily dose) is FDA-approved for functional bowel/irritable bowel syndrome, with 82% of patients demonstrating favorable clinical response compared to 55% with placebo 2
• Antispasmodics play a central role in treating functional abdominal cramping pain by directly addressing the cramping component 4

Second-Line: Neuromodulators for Refractory Cases

• Tricyclic antidepressants (TCAs) are recommended when antispasmodics provide inadequate relief, as they modulate central pain perception 3, 6
• Gabapentin or pregabalin with appropriate renal dose adjustments are recommended for neuropathic pain components or central sensitization features 1, 9, 3
• Duloxetine (serotonin-norepinephrine reuptake inhibitor) may be considered, particularly when comorbid depression is present 9, 3

Adjunctive Analgesics

• Acetaminophen up to 3 g/day is the safest first-line analgesic option for additional pain relief 1
• NSAIDs may be used cautiously but should be avoided in patients with gastrointestinal symptoms due to risk of mucosal injury 1, 9

Interdisciplinary Team Approach

• Develop an interdisciplinary team including primary care provider, gastroenterologist, pain psychologist, and physical therapist for complex cases 5, 1
• Team-based care is particularly important when patients have co-occurring psychiatric disorders or when initial treatments fail 5, 1

Monitoring and Follow-Up Strategy

Establishing Functional Goals

• Focus assessments on achieving functional goals (return to work, social activities, exercise capacity) rather than pain severity alone 5, 1
• Use the PEG tool at each visit to track pain intensity, interference with enjoyment of life, and interference with general activity 5, 1
• Regular reassessments should evaluate comfort, function, and treatment-related adverse events 5, 1

Managing New Pain Reports

• Any new report of pain in a patient with existing functional abdominal pain requires thorough reevaluation—do not simply increase current medications 5, 1
• Determine whether new pain represents: worsening of current pathology, development of new organic pathology, treatment failure (end-of-dose failure or tolerance), pain not responsive to current treatment requiring different approach, or intercurrent life event interfering with usual pain self-management 5
• Document the new symptom clearly and consider consultation with a pain specialist if available 5

Critical Pitfalls to Avoid

Medication-Related Pitfalls

• Never prescribe opioids for functional abdominal pain—they worsen gastrointestinal dysmotility, provide no long-term benefit, and carry significant risk of opioid use disorder 10, 1, 9
• Avoid focusing solely on pharmacological management without addressing physical function and psychological factors, as this delays implementation of evidence-based treatments 1, 9
• Do not neglect screening for unhealthy substance use, as this requires consultation with addiction specialists 1

Diagnostic and Therapeutic Relationship Pitfalls

• Build therapeutic partnership through empathy, reflective listening, and believing the patient's pain expression—pain is subjective and validation is therapeutic 10, 1
• Avoid dismissing functional pain as "not real" or purely psychological; explain the neurobiological basis while acknowledging the biopsychosocial model 5, 8
• Do not perform excessive diagnostic testing once functional diagnosis is established, as this reinforces illness behavior and delays effective treatment 8

Treatment Approach Pitfalls

• Avoid delaying CBT or other psychological interventions until "everything else has failed"—these are first-line treatments, not last resort 1, 3
• Do not treat new pain symptoms as simply requiring dose escalation of existing medications without proper reevaluation 5
• Recognize "pseudo-addiction" (medication-seeking behavior due to inadequate pain control) and maintain nonjudgmental perspective when assessing for aberrant behaviors 1