Bowel obstruction?

CTWSES Bologna 2018

Distension and vomiting; the surgeon is deciding between an NG tube with observation and an urgent laparotomy.

Answer the surgeon

NG tube and observation vs urgent operation — a closed-loop configuration or strangulation signs require urgent surgical assessment.

Your answer must state:

Obstruction present, and its grade — high-grade vs partial
Transition point location
Cause: adhesion (no mass at the transition), hernia, or tumor
Closed loop: yes or no
Ischemia signs: yes or no

Key and direct findings

1.Dilated small bowel with a transition point
Small bowel >2.5–3 cm proximal to a discrete transition point with collapsed loops beyond it.
2.Closed loop
C- or U-shaped fluid-filled loop, radially converging mesenteric vessels, two adjacent transition points, or a whirl sign — this configuration is at high risk for strangulation and warrants urgent surgical assessment.
3.Strangulation signs
Reduced or absent wall enhancement compared with adjacent loops, mesenteric edema and haziness, ascites; pneumatosis and portomesenteric venous gas are late signs.
Pitfall: Judge enhancement on the portal-venous phase and beware globally poor enhancement from low cardiac output.

Supportive signs & checks

1.Small-bowel feces sign
Feculent material in a dilated loop marks the segment just proximal to the transition — use it to find the point.
2.Name the cause
Look for a hernia (check the groins and any scars) or a mass at the transition; an abrupt transition with neither, in a patient with prior surgery, is adhesional by exclusion.
Pitfall: Adhesions are invisible on CT — the diagnosis is made by what is absent at the transition point.
3.Distinguish ileus
Uniformly dilated small and large bowel without a transition point is ileus, not obstruction.

Wet-read snippets

Fill the blanks, then copy into your preliminary report.

Positive

High-grade small-bowel obstruction, transition point in the ___ with ___ (adhesional pattern / hernia / mass). No closed loop; bowel-wall enhancement preserved — no CT signs of strangulation.

Negative

No dilated small bowel or transition point — no CT evidence of obstruction.

Sources

Bologna guidelines for adhesive small bowel obstruction (2017 update) — Ten Broek RPG et al. World J Emerg Surg (2018)
Review: small-bowel obstruction — the diagnosis and when to worry — Paulson EK, Thompson WM. Radiology (2015)

Content review: Content pending clinical review · 2026-07-15

Educational reference for trained clinicians. Verify every result against the cited original guideline before use. Not a substitute for clinical judgment or medical advice.