What could be causing intermittent sharp pain under the left ribs radiating to the abdomen at night?

Intermittent Sharp Left-Sided Pain Under Ribs to Abdomen at Night

The most likely diagnosis is slipping rib syndrome (SRS), a frequently overlooked musculoskeletal condition that causes intermittent sharp pain in the lower chest and upper abdomen, particularly when the pain is positional, occurs with specific movements, and has persisted for weeks without systemic symptoms like fever. 1, 2

Clinical Reasoning and Differential Diagnosis

The key distinguishing features of this presentation point away from serious intra-abdominal pathology:

• Timing pattern (night only): Pain that occurs exclusively at night suggests a positional or musculoskeletal etiology rather than inflammatory conditions like diverticulitis, which typically cause constant pain with fever and leukocytosis 3
• Intermittent nature: The waxing-waning pattern over 2 weeks without progression argues against acute surgical conditions like perforation, abscess, or bowel obstruction 3
• Sharp quality: Sharp, well-localized pain is an indicator of a less severe condition according to European Heart Journal guidelines, particularly when it varies with body position 3

Primary Diagnosis: Slipping Rib Syndrome

SRS should be your leading diagnosis because it characteristically presents with intermittent sharp pain in the lower chest/upper abdomen that worsens with specific movements or positions (such as lying down at night). 1, 2

Diagnostic Approach:

• Perform the hooking maneuver: Hook your fingers under the lower costal margin (ribs 8-10) and pull anteriorly while the patient is supine—reproduction of the exact pain confirms SRS with high specificity 1, 2
• Palpate the costal margin systematically: Apply firm pressure along the entire costal margin to identify a tender spot; reproduction of pain at this spot is diagnostic 4
• Dynamic ultrasound can confirm the diagnosis by visualizing hypermobility of the lower ribs slipping over adjacent ribs, though this is rarely necessary when clinical findings are positive 1, 2

Management:

• Reassurance that this is a benign musculoskeletal condition requiring no imaging in the absence of alarm features 1, 2
• Avoid postures that worsen pain, particularly positions that stress the lower ribs 1
• NSAIDs or acetaminophen for symptomatic relief, though many patients report minimal benefit 1
• Intercostal nerve blocks with local anesthetic and corticosteroids for refractory cases 5
• Surgical resection of the slipping rib cartilages is reserved for debilitating, treatment-resistant pain 2

When to Consider Imaging

You should NOT order imaging if the hooking maneuver is positive and there are no alarm features. 1, 4 However, imaging becomes necessary if:

• Fever, leukocytosis, or systemic symptoms are present—obtain CT abdomen/pelvis with IV contrast to evaluate for diverticulitis, abscess, or other inflammatory conditions 3
• Age >50 years with new-onset pain—consider CT to exclude malignancy or other serious pathology 3
• Progressive worsening despite conservative management—CT can identify alternative diagnoses 3
• Rebound tenderness or peritoneal signs—immediate CT is mandatory to exclude perforation or surgical abdomen 6

Alternative Diagnoses to Consider

If the hooking maneuver is negative, consider:

Gastrointestinal Causes:

• Splenic pathology (splenic infarct, subcapsular hematoma)—would typically cause constant pain, not intermittent 6
• Gastric or pancreatic disease—pain would likely be postprandial rather than exclusively nocturnal 6
• Diverticulitis—extremely unlikely without fever, leukocytosis, or constant pain; only 25% of diverticulitis patients present with the classic triad of left lower quadrant pain, fever, and leukocytosis 3

Musculoskeletal Causes:

• Costochondritis—presents with anterior chest wall tenderness but lacks the clicking/slipping sensation 3
• Rib fracture—would have acute onset related to trauma or severe coughing 3

Renal Causes:

• Nephrolithiasis—would cause colicky pain radiating to the groin, not intermittent sharp pain under ribs 3

Critical Pitfalls to Avoid

• Do not order extensive imaging (CT, MRI, ultrasound) before performing a thorough physical examination with the hooking maneuver—33% of SRS patients in one series were referred for repeat investigations despite a firm clinical diagnosis 4
• Do not assume left-sided pain cannot be musculoskeletal—SRS accounts for 3% of new referrals to gastroenterology clinics and is commonly misdiagnosed 4
• Do not perform cholecystectomy or other surgical procedures without confirming the diagnosis—8 patients in one series underwent unnecessary cholecystectomy for undiagnosed SRS 4
• Do not dismiss the diagnosis if initial conservative management fails—70% of patients continue to have pain at 4-year follow-up but learn to manage it with reassurance and activity modification 4

When to Escalate Care

Immediate imaging with CT abdomen/pelvis with IV contrast is required if:

• Fever develops (suggests infection/inflammation) 3
• Pain becomes constant rather than intermittent (suggests progressive pathology) 3
• Peritoneal signs emerge (rebound, guarding, rigidity) 6
• Patient develops nausea, vomiting, or inability to pass gas/stool (suggests obstruction) 3