What is the diagnosis and management for an adult patient with a history of possible gastrointestinal disease, presenting with early satiety, thick stools, pulsating abdominal pain primarily in the right upper quadrant (RUQ), and bloating?

Differential Diagnosis and Management Approach

This patient's constellation of early satiety, bloating, thick stools, and pulsating RUQ pain requires urgent imaging with ultrasound to exclude life-threatening vascular pathology (particularly abdominal aortic aneurysm given the pulsating quality), followed by systematic evaluation for biliary disease, small intestinal dysmotility, or functional dyspepsia based on imaging findings.

Immediate Priority: Exclude Vascular Emergency

The pulsating quality throughout the abdomen, particularly in the RUQ, is a red flag that demands immediate attention:

• Obtain abdominal ultrasound immediately to evaluate for abdominal aortic aneurysm or other vascular pathology, as pulsating abdominal pain can indicate life-threatening conditions requiring urgent intervention 1, 2
• If ultrasound is technically limited or concerning findings are present, proceed directly to CT abdomen/pelvis with IV contrast for definitive vascular assessment 3, 1

Primary Differential Diagnoses

1. Biliary Disease (Most Common RUQ Cause)

Biliary pathology accounts for approximately two-thirds of RUQ pain cases 1:

• Acute cholecystitis: Look for fever, leukocytosis, positive Murphy's sign on physical exam 1, 2
• Biliary colic: Episodic severe pain radiating to right shoulder or back 1
• Ultrasound is the first-line test (96% accuracy for gallstones) and should evaluate for gallbladder wall thickening, pericholecystic fluid, and sonographic Murphy's sign 1, 2, 4

Critical pitfall: CT has only 75% sensitivity for gallstones, so negative CT does not exclude cholelithiasis—always use ultrasound as first-line 1

2. Small Intestinal Dysmotility/Chronic Intestinal Pseudo-Obstruction

The combination of early satiety, bloating, and thick stools strongly suggests a motility disorder 3:

• Classic presentation: Early satiety, bloating, abdominal distension, alternating diarrhea and constipation are hallmark symptoms of intestinal myopathy 3

• Initial workup must exclude organic obstruction first:

  • Plain abdominal radiographs to assess for dilated bowel 3
  • CT abdomen/pelvis with contrast to exclude mechanical obstruction and identify transition points 3
  • Screen for secondary causes: thyroid function, celiac disease (anti-tissue transglutaminase), diabetes, electrolytes (potassium, magnesium) 3

• Advanced testing if dysmotility suspected:

  • Antibodies for scleroderma (anti-centromere, anti-Scl70) and connective tissue disorders 3
  • Paraneoplastic antibodies (ANNA-1, anti-CRMP-5, ganglionic AChR) if autonomic dysfunction present 3
  • Small bowel manometry is the definitive test for pseudo-obstruction 3

3. Functional Dyspepsia with Postprandial Distress Syndrome

If structural disease is excluded, consider functional dyspepsia 3:

• Rome IV criteria for PDS: Bothersome postprandial fullness and/or early satiation occurring at least 3 days per week, with symptoms active in past 3 months and onset at least 6 months prior 3
• Early satiety and bloating are cardinal features of PDS subtype 3, 5
• Diagnosis requires upper endoscopy to exclude structural disease 3

Diagnostic Algorithm

Step 1: Urgent Assessment (Within Hours)

• Physical examination: Check vital signs, assess for peritoneal signs, palpate for pulsatile masses, elicit Murphy's sign 1, 2, 4
• Laboratory tests: CBC with differential, comprehensive metabolic panel, liver function tests, lipase, pregnancy test (if applicable) 2

Step 2: Imaging Based on Clinical Presentation

If pulsating pain is prominent or patient appears ill:

• CT abdomen/pelvis with IV contrast immediately to evaluate vascular structures and exclude emergencies 3, 1

If biliary disease suspected (RUQ tenderness, Murphy's sign, fever):

• Right upper quadrant ultrasound as first-line test 3, 1, 2
• If ultrasound equivocal and clinical suspicion high, proceed to HIDA scan (96% sensitivity, 90% specificity) or CT with IV contrast 1

If dysmotility suspected (early satiety, bloating, thick stools without acute findings):

• Plain abdominal radiographs first to assess bowel gas pattern 3
• CT abdomen/pelvis with oral and IV contrast to exclude mechanical obstruction 3

Step 3: Specialized Testing Based on Initial Results

If imaging shows dilated bowel without obstruction:

• Screen for secondary causes: TSH, anti-tissue transglutaminase, HbA1c, electrolytes 3
• Consider autoimmune workup: ANA, scleroderma antibodies, paraneoplastic panel 3
• Refer to gastroenterology for small bowel manometry if chronic intestinal pseudo-obstruction suspected 3

If all structural testing negative:

• Upper endoscopy to exclude peptic disease and establish functional dyspepsia diagnosis 3
• Consider gastric emptying study if gastroparesis suspected 3

Critical Pitfalls to Avoid

• Never assume negative CT excludes gallstones—ultrasound is required for biliary evaluation 1
• Do not order CT without IV contrast for suspected cholecystitis, as critical findings like gallbladder wall enhancement cannot be detected 1
• Murphy's sign has limited diagnostic power (positive likelihood ratio only 2.8) and may be absent in elderly, diabetic, or immunocompromised patients despite severe disease 4
• Prior pain medication invalidates Murphy's sign reliability, making timing of examination crucial 4
• Do not diagnose dysmotility without excluding mechanical obstruction first, as this fundamentally changes management 3
• Recognize that multiple laparotomies may be performed before chronic intestinal pseudo-obstruction is diagnosed—maintain high index of suspicion 3

Urgent Referral Indications

Immediate surgical consultation if:

• Fever with leukocytosis suggesting acute cholecystitis or cholangitis 1
• Peritoneal signs suggesting perforation 1
• Pulsatile mass or imaging evidence of vascular pathology 1

Gastroenterology referral if:

• Chronic symptoms with suspected dysmotility disorder 3
• Functional dyspepsia requiring specialized management 3
• Need for advanced testing (manometry, endoscopy) 3