What is the appropriate evaluation and management for a 35-year-old male with 2 months of daily abdominal pain, nausea, and vomiting?

Evaluation and Management of Chronic Abdominal Pain with Nausea and Vomiting in a 35-Year-Old Male

This patient requires urgent CT scan of the abdomen and pelvis with IV contrast to exclude life-threatening surgical emergencies, followed by upper endoscopy to rule out mechanical obstruction, and then gastric emptying scintigraphy if initial imaging is negative. 1

Immediate Diagnostic Priorities

Rule Out Surgical Emergencies First

The combination of 2 months of daily abdominal pain, recurrent vomiting episodes severe enough to cause work absences, and impaired glucose (118 mg/dL suggesting prediabetes/diabetes) creates a clinical picture that demands exclusion of serious pathology before attributing symptoms to functional disorders. 1

CT abdomen and pelvis with IV contrast is the mandatory first test because:

• The severity and chronicity of symptoms with functional impairment (missing work 3 times) indicates potentially significant intra-abdominal pathology 1
• CT has superior sensitivity for detecting mechanical obstruction, bowel wall thickening, mesenteric fat streaking, and other structural abnormalities 2
• While acute mesenteric ischemia classically presents with "pain out of proportion to exam," chronic mesenteric ischemia presents with postprandial abdominal pain, nausea, vomiting, and early satiety—matching this patient's presentation 2
• The impaired fasting glucose (118) raises concern for diabetic complications affecting the GI tract 3

Upper Endoscopy After CT

If CT is negative, proceed immediately to upper endoscopy (EGD) because:

• Endoscopy is mandatory to rule out mechanical obstruction before diagnosing any motility or functional disorder 3
• The patient's age (35 years) is below the typical threshold for immediate endoscopy based on gastric cancer risk in Western populations (typically 45-50 years), but the severity and duration of symptoms with functional impairment warrant investigation 2
• Endoscopy can identify peptic ulcer disease, gastric outlet obstruction, or other structural lesions causing these symptoms 2

Gastroparesis Evaluation

When to Test for Gastroparesis

If both CT and endoscopy are negative, gastric emptying scintigraphy is the next essential test because this patient's symptom pattern—postprandial nausea, vomiting episodes, and decreased appetite—is highly consistent with gastroparesis. 3

The impaired fasting glucose (118 mg/dL) is particularly concerning because:

• Diabetic gastroparesis is one of the three most common etiologies (diabetic, idiopathic, postsurgical) 3
• Hyperglycemia itself can slow gastric emptying, creating a vicious cycle 3

Proper Testing Technique

Gastric emptying scintigraphy must be performed correctly or results are meaningless:

• Test duration must be at least 2 hours, with 4-hour testing providing higher diagnostic yield and accuracy 3
• Shorter test durations (<2 hours) are inaccurate and should not be used 3
• Use a standardized low-fat egg white meal labeled with 99mTc sulfur colloid, consumed with jam and toast 3
• Withdraw all medications that influence gastric emptying for 48-72 hours prior to testing 3
• Monitor and control blood glucose during the test—hyperglycemia can falsely slow gastric emptying 3
• Avoid smoking on test day 3

Critical pitfall: Normal gastric emptying does not rule out gastropathy—symptoms may still be present despite normal emptying rates. 3

Pre-Testing Preparation and Concurrent Evaluation

Blood Glucose Management

Check HbA1c immediately to determine if this patient has undiagnosed diabetes, as the fasting glucose of 118 mg/dL indicates prediabetes at minimum. 3 Diabetic gastroparesis requires different management considerations and glycemic control directly affects gastric motility. 3

Medication Review

Verify the patient is truly not taking any medications that could cause these symptoms:

• Opioids are a common cause of delayed gastric emptying and must be excluded 3
• Anticholinergics can worsen gastric dysmotility 3
• Even over-the-counter medications or supplements should be reviewed 2

Nutritional Assessment

Document current nutritional status:

• Calculate BMI and percentage weight loss over the past 2 weeks, 3 months, and 6 months 2
• The patient reports "decreased appetite" but denies weight loss—verify this objectively 2
• If vomiting has been severe enough to keep him awake and cause work absences, nutritional compromise is likely 3

Differential Diagnosis Considerations

Functional Dyspepsia

Functional dyspepsia is defined by Rome IV criteria as bothersome epigastric pain, burning, postprandial fullness, or early satiation without structural disease. 3 However, this diagnosis can only be made after excluding structural and motility disorders through appropriate testing. 2, 3

The patient's symptoms overlap with functional dyspepsia, but the severity (missing work, nocturnal vomiting) and chronicity (2 months daily) warrant thorough investigation first. 2

Chronic Mesenteric Ischemia

While less common in a 35-year-old, chronic mesenteric ischemia classically presents with:

• Postprandial abdominal pain 30-60 minutes after eating 2
• Nausea and vomiting 2
• Early satiety 2
• Food avoidance (which could explain "decreased appetite") 2

CT angiography (CTA) has 95-100% sensitivity and specificity for detecting mesenteric vessel stenosis and should be considered if standard CT with IV contrast shows any vascular abnormalities. 2

Small Intestinal Dysmotility

If gastroparesis testing is negative but symptoms persist, consider broader intestinal dysmotility:

• Screen for hypothyroidism, celiac disease, and diabetes (beyond just glucose) 2
• Check for connective tissue disorders (ANA, anti-centromere, anti-Scl70) 2
• Consider autonomic dysfunction testing if orthostatic symptoms are present 2

Symptomatic Management During Workup

Antiemetic Therapy

Ondansetron 8 mg orally can be used for symptomatic relief of nausea and vomiting during the diagnostic workup:

• Ondansetron is FDA-approved for prevention of nausea and vomiting 4
• Dose is 8 mg administered 30 minutes before situations likely to trigger symptoms 4
• Critical warning: Ondansetron can mask progressive ileus and gastric distension—it should not be used as a substitute for diagnostic evaluation 4
• Monitor for QT prolongation, especially if electrolyte abnormalities are present 4
• Avoid in patients with congenital long QT syndrome 4

Dietary Modifications

While awaiting test results, implement gastroparesis-friendly dietary changes:

• Smaller, more frequent meals with lower fat and fiber content 3
• Maintain adequate hydration (≥1.5 L fluids/day) 3
• Separate liquids from solids during meals 3
• Eat slowly with meal duration ≥15 minutes 3

Critical Pitfalls to Avoid

Do not empirically treat with acid suppression (PPIs) without establishing a diagnosis first—this delays potentially life-saving intervention if a surgical emergency is present. 1

Do not attribute symptoms to "functional dyspepsia" or "stress" without completing the diagnostic algorithm—the severity and functional impairment demand thorough investigation. 2, 3

Do not rely on symptom patterns alone to differentiate between structural and functional disease—symptom clusters have poor predictive value for underlying pathology. 2

Do not use opioids for pain management—they worsen gastric emptying and will confound diagnostic testing. 3

Do not order gastric emptying scintigraphy before ruling out mechanical obstruction with endoscopy—this is a fundamental error in the diagnostic sequence. 3