What diagnostic workup is recommended for a patient with suspected pyloric stenosis?

Abdominal ultrasound is the preferred diagnostic workup for a patient with suspected pyloric stenosis because it is a non-invasive and highly effective imaging tool that can accurately visualize the pylorus. In cases of pyloric stenosis, the ultrasound will typically reveal a thickened pyloric muscle and characteristics like an elongated pylorus or “string sign,” which are classic indicators of this condition.

Other options such as chest X-ray and CT scan of the abdomen are not routinely used in the diagnosis of pyloric stenosis. A chest X-ray would not provide adequate information about the pylorus and is generally focused on the lungs and heart. Similarly, while a CT scan could potentially provide visualization of abdominal structures, it involves exposure to radiation and is not necessary when an ultrasound can provide definitive answers. An electrolyte panel alone, while useful for assessing the patient's hydration status or metabolic state, cannot confirm the diagnosis of pyloric stenosis, as it does not provide structural imaging of the gastrointestinal tract. Hence, abdominal ultrasound stands out as the most appropriate and effective investigation for suspected pyloric stenosis.