How do you inspect, palpate, and auscultate a patient with a suspected gastric outlet obstruction?

Physical Examination of Gastric Outlet Obstruction

In a patient with suspected gastric outlet obstruction, inspect for visible gastric distension and a succussion splash, palpate for epigastric fullness or a palpable mass, and auscultate for high-pitched bowel sounds or a succussion splash on gentle shaking of the abdomen.

Inspection

• Look for visible epigastric distension which may be progressive in onset, particularly in malignancy-related gastric outlet obstruction 1
• Assess the patient's general appearance including facial expression, skin color and temperature, and mental status, as these may indicate critical conditions such as hypovolemic shock from prolonged vomiting 1
• Examine for signs of dehydration including dry mucous membranes, poor skin turgor, and sunken eyes 1
• Inspect all hernia orifices (umbilical, inguinal, femoral) and all laparotomy/laparoscopy incision scars, as hernias can mimic or coexist with gastric outlet obstruction 1
• Look for cachexia or signs of malnutrition, which may suggest chronic obstruction from malignancy 1

Palpation

• Palpate the epigastrium for a palpable mass, which may indicate gastric malignancy as the underlying cause, since malignancy is now the most common cause of gastric outlet obstruction in adults 1
• Assess for epigastric tenderness, which is characteristic of gastric outlet obstruction 2
• Check for peritoneal signs (guarding, rigidity, rebound tenderness), as their presence indicates ischemia and/or perforation requiring emergent surgical exploration 1
• Palpate for hepatomegaly or other abdominal masses that may suggest metastatic disease 1
• Assess abdominal distension, which has a positive likelihood ratio of 16.8 for bowel obstruction 1

Auscultation

• Auscultate for high-pitched or tinkling bowel sounds, which may be present early in obstruction 1
• Listen for absent bowel sounds, which may indicate ileus or advanced obstruction 1
• Perform the succussion splash test by gently shaking the patient's abdomen while auscultating over the epigastrium; a positive splash indicates retained gastric contents and is highly suggestive of gastric outlet obstruction 2

Additional Critical Examination Components

• Perform digital rectal examination to detect blood or a rectal mass that might suggest colorectal malignancy as a cause of distal obstruction 1
• Assess vital signs carefully: tachycardia, tachypnea, cool extremities, mottled or cyanotic skin, slow capillary refill, and oliguria indicate shock and require immediate intervention 1
• Check for fever, which may indicate complications such as perforation or ischemia 1

Common Pitfalls to Avoid

• Do not assume benign disease; malignancy is now the predominant cause of gastric outlet obstruction in adults due to widespread use of H2 blockers and proton pump inhibitors reducing peptic ulcer disease 1, 2
• Normal vital signs and absence of peritoneal signs do not exclude ischemia, as laboratory markers like elevated lactate and leukocytosis may be more sensitive 1
• A negative abdominal examination does not rule out gastric outlet obstruction; clinical suspicion should prompt imaging with CT abdomen and pelvis with IV contrast and neutral oral contrast 1