GI imaging: toxic megacolon: practice question

A Radiology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Radiology · GI imaging: toxic megacolon

Sample item

A patient with severe colitis has fever and tachycardia, and an abdominal radiograph shows a transverse colon diameter of 7 cm with loss of haustra. Which is the correct interpretation?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

C. Toxic megacolon, with risk of perforation

A transverse colon diameter above 6 cm with systemic toxicity indicates toxic megacolon in the setting of colitis. Barium enema and colonoscopy are contraindicated because of perforation risk. Management includes steroids, fluids and urgent surgical review.

Option by option

  • A. Paralytic ileus of small bowel

    The description involves the colon, not just the small bowel.

  • B. Chilaiditi sign

    Chilaiditi is interposition of colon under the diaphragm.

  • C. Toxic megacolon, with risk of perforation (correct)

    Correct. A transverse colon above 6 cm in a toxic patient is toxic megacolon.

  • D. Normal colon

    A normal colon is under 6 cm.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

More Radiology questions

Questions about this Radiology question

What is the answer to this Radiology question?

The best answer is C, Toxic megacolon, with risk of perforation. A transverse colon diameter above 6 cm with systemic toxicity indicates toxic megacolon in the setting of colitis.

Why is "Paralytic ileus of small bowel" not the answer?

The description involves the colon, not just the small bowel.

Why is "Chilaiditi sign" not the answer?

Chilaiditi is interposition of colon under the diaphragm.

Why is "Normal colon" not the answer?

A normal colon is under 6 cm.

What concept does this question test?

It tests GI imaging: toxic megacolon in Radiology. Barium enema and colonoscopy are contraindicated because of perforation risk. Management includes steroids, fluids and urgent surgical review.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study GI imaging: toxic megacolon?

Learn signs with the image, and the disease they point to. Then use the flashcards and the other Radiology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.