What sign indicates a hypertrophic pyloric stenosis?

The sign that indicates hypertrophic pyloric stenosis is the double bubble sign. This radiological finding is observed on an abdominal X-ray and is characterized by the presence of two air-filled structures: the distended stomach and the proximal duodenum, which are separated by the obstructed pylorus.

In hypertrophic pyloric stenosis, the muscular layer of the pylorus becomes hypertrophied, leading to narrowed passage from the stomach into the duodenum. As a result, gastric content builds up, causing a distended stomach, while the obstructed pylorus prevents the contents from passing into the duodenum, leading to the appearance of a second bubble in the proximal duodenum that is also filled with air.

The other signs mentioned do not specifically relate to hypertrophic pyloric stenosis:

• The bird beak sign is associated with conditions like achalasia, where there is a narrowing at the lower esophagus.

• The single bubble sign is indicative of conditions like congenital duodenal atresia but does not reflect the specific pattern associated with pyloric stenosis.

• The swallowed sign does not correlate with a specific radiological finding related to hypertrophic pyloric stenosis.

Thus, the presence of the double bubble