How to diagnose and manage a patient with epigastric abdominal pain, abnormal LFTs, and complex medical history including chronic fatigue syndrome, fibromyalgia, and IBS?

Diagnosis: Centrally Mediated Abdominal Pain Syndrome (CAPS) with Functional Overlay

This patient's presentation—with fluctuating LFTs that have normalized, negative imaging including normal HIDA scan, comorbid fibromyalgia/chronic fatigue syndrome/IBS, and episodic severe pain without identifiable triggers—is most consistent with centrally mediated abdominal pain syndrome rather than structural biliary disease, and should be managed with neuromodulators and brain-gut behavioral therapies rather than cholecystectomy. 1

Why This Is NOT Biliary Disease

• Normal HIDA scan with visualization of gallbladder, no cystic duct obstruction, and normal ejection fraction definitively excludes functional gallbladder disorder 2
• The British Society of Gastroenterology explicitly warns against misattribution of functional dyspepsia symptoms to gallstones, noting this leads to unnecessary surgery 2
• Pain unrelated to eating argues strongly against biliary colic, which characteristically occurs 30-90 minutes postprandially 2
• Completely normalized LFTs on most recent testing make ongoing hepatobiliary pathology extremely unlikely 3

Recognizing the Central Pain Pattern

The constellation of fibromyalgia, chronic fatigue syndrome, and IBS represents overlapping functional disorders with shared central sensitization mechanisms. 4, 5

• Between 20-50% of IBS patients have comorbid fibromyalgia; conversely, 77% of fibromyalgia patients have lifetime IBS 2
• These patients have 5.33-fold increased odds of fibromyalgia and 5.40-fold increased odds of chronic fatigue syndrome compared to general population 4
• The polysymptomatic nature (epigastric pain, nausea, vomiting, constipation with opioids, migraines) indicates somatization and central amplification of visceral signals 2, 5
• Episodic severe pain without identifiable triggers, starting during stress, that resolves spontaneously suggests centrally mediated mechanisms rather than structural pathology 1

Critical Diagnostic Pitfall to Avoid

The British Society of Gastroenterology specifically identifies patients with severe or refractory IBS and overlapping functional disorders as being at risk for iatrogenic harm from unnecessary surgery. 2

• The guideline explicitly states: "Iatrogenic harms due to opioid prescribing, unnecessary surgery and unproven unregulated diagnostic or therapeutic approaches should be avoided" 2
• Cholecystectomy in this setting will not resolve centrally mediated pain and may worsen symptoms through additional surgical trauma and opioid exposure 2
• The narcotic bowel syndrome risk is particularly concerning given her current opioid use for pain episodes 2, 1

Recommended Management Algorithm

Step 1: Confirm Functional Diagnosis and Stop Further Testing

• Review diagnosis with patient, explaining that pain is real but involves central nervous system amplification of normal gut signals 1
• Establish that basic workup (imaging, LFTs, HIDA) has excluded structural disease requiring surgery 1
• Stop pursuing additional invasive testing, as this reinforces illness behavior and delays appropriate treatment 2, 1

Step 2: Initiate Neuromodulator Therapy

Start low-dose tricyclic antidepressant (amitriptyline or nortriptyline) 10-25 mg at bedtime, titrating slowly every 1-2 weeks based on response and tolerability. 1

• TCAs are first-line for centrally mediated abdominal pain through descending pain modulation pathways 1
• If TCAs are not tolerated due to anticholinergic effects, switch to duloxetine (SNRI) 30-60 mg daily 1
• Absolutely avoid opioids, as they worsen outcomes and risk narcotic bowel syndrome in functional gastrointestinal disorders 2, 1

Step 3: Refer for Brain-Gut Behavioral Therapy

Initiate cognitive behavioral therapy (CBT) or gut-directed hypnotherapy concurrently with pharmacotherapy. 2

• IBS-specific CBT and gut-directed hypnotherapy both have strong evidence for global symptom improvement in IBS and overlapping functional disorders 2
• These therapies address catastrophizing, pain-related fear avoidance, and maladaptive cognitive processes maintaining symptoms 2, 1
• Psychological therapies should be offered early rather than waiting 12 months, particularly given multiple comorbid functional disorders 2
• Mindfulness-based stress reduction can be added for stress management 2, 1

Step 4: Address Migraine Medication Overuse

• Frequent triptan use (4-5 times monthly) approaches medication overuse headache threshold 1
• Consider prophylactic migraine therapy (which may also help abdominal pain if using amitriptyline or duloxetine) 1

Step 5: Multidisciplinary Escalation if Needed

If symptoms remain severe despite initial neuromodulator and behavioral therapy, refer to multidisciplinary chronic pain team. 2, 1

• Severe or refractory functional disorders require integrated multidisciplinary approach 2
• Consider combination neuromodulators (augmentation) such as duloxetine plus gabapentin for refractory symptoms, monitoring vigilantly for serotonin syndrome 2, 1
• Referral to chronic pain team is particularly important if opioid reduction is needed 2

What About the Weight Loss?

• 40-pound weight loss over 4 months on [MEDICATION—likely GLP-1 agonist] is expected pharmacologic effect 3
• However, ensure no alarm features: no progressive dysphagia, no evidence of malignancy on imaging, age and symptom pattern do not mandate urgent endoscopy given normal recent workup 2, 3
• If weight loss continues or new alarm features develop, reconsider endoscopy 2

Communication Strategy

Establish collaborative, empathic relationship acknowledging that pain is real and multifactorial, not dismissing it as "psychological." 1

• Explain that the brain's pain processing system requires treatment, using gut-brain axis framework 2, 1
• Emphasize that cure is unlikely but substantial improvement in symptoms and quality of life is achievable with appropriate treatment 2
• Frame neuromodulators as "pain medications that work on nerve pathways" rather than "antidepressants" to improve acceptance 1