In a patient without prior biliary colic who has constipation and a soft, non‑tender abdomen, does a positive Murphy’s sign indicate peritoneal irritation?

A Positive Murphy's Sign in This Clinical Context Does NOT Reliably Indicate Peritoneal Irritation

In a patient with constipation, no biliary history, and an otherwise soft abdomen, an isolated positive Murphy's sign has poor specificity and should not be interpreted as a true sign of peritoneal irritation or acute cholecystitis. You must pursue further diagnostic workup rather than relying on this single clinical finding.

Why Murphy's Sign Alone Is Insufficient

The 2020 World Society of Emergency Surgery guidelines explicitly state that no single clinical or laboratory finding has sufficient diagnostic power to establish or exclude acute cholecystitis 1. The evidence is clear:

• Murphy's sign has a positive likelihood ratio of only 2.8 (95% CI 0.8-8.6), with confidence intervals that cross 1.0, indicating weak diagnostic value 1
• The specificity is remarkably low at 35-53% in various studies 2, 3
• The positive predictive value is only 43-72.5%, meaning more than half of positive Murphy's signs may be false positives 3, 4

Critical Context: Your Patient's Presentation

Your patient has several features that make acute cholecystitis even less likely:

• No history of biliary colic (most acute cholecystitis patients have prior symptoms)
• Soft abdomen overall (suggests absence of diffuse peritoneal irritation)
• Constipation present (can cause right upper quadrant discomfort and false-positive Murphy's sign)

The ACR Appropriateness Criteria emphasize that Murphy's sign has "relatively low specificity for acute cholecystitis" and should never be used in isolation 2.

What This Positive Murphy's Sign Actually Means

A positive Murphy's sign in your clinical scenario likely represents:

1. Localized tenderness from constipation-related colonic distension affecting the hepatic flexure
2. Musculoskeletal pain referred to the right upper quadrant
3. Non-specific abdominal wall tenderness
4. False positive (occurs in 65-77% of cases without acute cholecystitis) 3

Recent evidence confirms that overreliance on the sonographic Murphy sign results in surprisingly low diagnostic accuracy in practice 5.

Your Diagnostic Algorithm

Step 1: Obtain right upper quadrant ultrasound immediately 1, 2

• Look for gallstones, wall thickening (>3mm), pericholecystic fluid, wall hyperemia
• A normal gallbladder appearance makes acute pathology very unlikely 2

Step 2: Check inflammatory markers

• Elevated WBC and CRP support inflammation 1
• Normal labs in your constipated patient with soft abdomen further argue against acute cholecystitis

Step 3: Consider alternative diagnoses

• Constipation-related pain (most likely in your case)
• Fitz-Hugh-Curtis syndrome if sexually active female with pelvic symptoms 6
• Atypical presentations of other pathology 7

Common Pitfalls to Avoid

1. Do not diagnose acute cholecystitis based on Murphy's sign alone - this violates evidence-based guidelines 1
2. Do not assume peritoneal irritation without diffuse abdominal findings - true peritonitis presents with guarding, rigidity, and rebound tenderness throughout the abdomen
3. Do not overlook constipation as a cause of RUQ tenderness - colonic distension at the hepatic flexure commonly mimics biliary pathology
4. Remember that pain medication reduces Murphy's sign sensitivity - but your patient's soft abdomen suggests no significant inflammation regardless 2

The Bottom Line

Your patient's isolated positive Murphy's sign, in the context of constipation and an otherwise benign examination, does not indicate peritoneal irritation. The combination of findings must guide diagnosis, not a single physical exam maneuver with documented poor specificity. Obtain ultrasound and laboratory studies to definitively rule out biliary pathology, but the clinical picture strongly suggests a benign etiology related to constipation rather than acute cholecystitis or peritoneal inflammation.