Belly ache and Rigler’s Sign

Labs and Lytes 024

Author: Chris Sia
Reviewers: Sarah Yong and Chris Nickson

A middle-aged gentleman presents with abdominal pain and nausea.



Q1. Describe the x-ray findings?

This is an AP supine abdominal x-ray.

Key findings include:

  • Distended loops of small (5cm) and large (7.5cm) bowel
  • Rigler’s sign is positive, suggesting intra-peritoneal free gas (red arrow)
  • Nasojejunal tube in situ (yellow arrow)
  • Contrast present in the colon and rectum from previous imaging (orange arrow)

Click to enlarge

Click to enlarge

Q2. What is Rigler’s sign?

Riglers sign (aka double-wall sign) is present when both sides of a bowel wall can be visualised, due to delineation by air on either side. It is a good indication of free intraperitoneal gas.

However, the sensitivity for detecting perforation on AXR is low and is best confirmed as subdiaphragmatic air on erect CXR or with a CT scan.

In this case the intraperitoneal gas was the result of a gastric perforation from anastamotic breakdown complicating a prior partial gastrectomy.

Q3. What is the size of normal small bowel, colon and caecum?

Apply the 3-6-9 rule:

  • Small bowel < 3 cm
  • Colon <6cm
  • Caecum <9cm

Small bowel has a central location with valvulae conniventes visible. Large bowel is peripheral with haustra visible.


References and links

One comment to “Belly ache and Rigler’s Sign”
  1. There is increased lucency of the abdominal cavity with air seen on both sides of the bowel wall, making the bowel wall clearly demonstrated, so-called double wall sing of pneumoperitoneum. Also called the Rigler’s sign.

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