What could be causing left upper quadrant pain after eating fried food in an adult with potential risk factors for gastrointestinal disease?

Left Upper Quadrant Pain After Eating Fried Food

Primary Diagnostic Consideration

The most likely diagnosis is functional dyspepsia, which should be managed with H. pylori testing and eradication if positive, followed by proton pump inhibitor therapy if symptoms persist. 1, 2

Initial Clinical Assessment

The key clinical features to identify include:

• Pain characteristics: In functional dyspepsia, pain is typically in the upper abdomen or epigastrium, present during fasting and/or precipitated by meal ingestion, and is unrelated to defecation (unlike IBS) 1
• Associated symptoms: Early satiety, postprandial fullness, or burning sensation in the upper abdomen 2
• Alarm features requiring urgent evaluation: Age ≥55 years with weight loss, dysphagia, hematemesis, treatment-resistant symptoms, anemia, or family history of gastro-oesophageal cancer 1

Differential Diagnosis to Exclude

While functional dyspepsia is most common with postprandial left upper quadrant pain after fatty foods, several conditions must be excluded:

• Splenic pathology: Requires CT abdomen/pelvis with IV contrast (rated 8/9 by ACR) for comprehensive evaluation 2, 3
• Pancreatic disease: Acute pancreatitis confirmed by lipase >2× upper limit or amylase >4× normal; CT with contrast for severity assessment 2
• Chronic mesenteric ischemia: Consider if postprandial pain occurs with weight loss and atherosclerotic risk factors; obtain CT angiography 2
• Splenic flexure colitis or diverticulitis: Can extend to left upper quadrant; diagnosed with CT 2
• Atypical appendicitis with malrotation: Rare but documented cause of left upper quadrant pain requiring CT for diagnosis 4

Recommended Imaging Strategy

CT abdomen and pelvis with IV contrast is the preferred initial imaging modality for left upper quadrant pain, providing comprehensive assessment with excellent diagnostic accuracy. 2, 3

• CT alters diagnosis in nearly 50% of cases and changes management in 25% of patients 3
• Plain radiography has very limited diagnostic value and is not recommended 2, 3
• Ultrasound has limited utility due to overlying bowel gas and rib shadowing, though may identify splenic or renal pathology 2

Management Algorithm

Step 1: Rule Out Alarm Features

• If age ≥55 with weight loss, dysphagia, anemia, or family history of upper GI malignancy → urgent endoscopy 1
• If fever and leukocytosis present → obtain CT with contrast to exclude intra-abdominal abscess 2

Step 2: Test and Treat H. pylori

• Test for H. pylori infection and treat with short course of antibiotic therapy if positive 2
• Reassess symptoms after successful eradication 1

Step 3: Empiric Acid Suppression

• If H. pylori negative or symptoms persist after eradication → initiate proton pump inhibitors (PPIs) or H2-receptor antagonists as first-line therapy 2

Step 4: Second-Line Options for Refractory Symptoms

• Tricyclic antidepressants (TCAs) to modulate pain perception at the gut-brain axis level 2
• Consider combination therapy with dual H1/H2 receptor antagonists or TCA combined with SSRI 2

Step 5: Specialist Referral

• Refer to gastroenterology for refractory symptoms for consideration of endoscopy, advanced prokinetics, or behavioral interventions 2

Common Pitfalls to Avoid

• Do not dismiss symptoms as benign without imaging when clinical suspicion exists, as CT can detect unexpected findings including malrotation with atypical appendicitis 2
• Do not rely solely on plain radiographs, which have poor sensitivity for most causes of left upper quadrant pain 3
• Do not attribute symptoms to gallstones without proper evaluation, as functional dyspepsia is often misattributed to other causes 1
• Do not delay appropriate imaging in elderly patients, who may present with atypical symptoms and normal laboratory values 3

Special Considerations

• Approximately one-third of patients with functional dyspepsia have overlapping gastroesophageal reflux symptoms, and clinicians tend to favor GORD diagnosis over functional dyspepsia in this situation 1
• Up to 50% of patients with functional dyspepsia have overlapping IBS, characterized by two different types of abdominal pain—one related and one unrelated to defecation 1
• Psychological factors, particularly anxiety, are associated with future development of functional dyspepsia 1