A 17-year-old adolescent female is 6 weeks postpartum. She presents to the emergency room with the complaints of increased jaundice, abdominal pain, nausea, vomiting, and fever. Her examination is remarkable for jaundice, pain of the right upper quadrant with guarding, and a clear chest. Chest radiographs appear normal. Which of the following tests is most likely to reveal the cause of this pain?

**Core Concept**
The patient's presentation is suggestive of postpartum hemorrhagic shock leading to liver dysfunction and potential complications such as liver laceration or infarction. The clinical scenario points towards acute right upper quadrant (RUQ) abdominal pain, likely due to complications of postpartum liver injury.

**Why the Correct Answer is Right**
The correct answer is **Option D: Liver function tests (LFTs) with liver ultrasound**. This combination is essential in evaluating liver dysfunction and potential complications such as liver laceration or hematomas. Liver function tests will help identify liver dysfunction, while a liver ultrasound will provide imaging of the liver to identify any structural abnormalities such as lacerations or hematomas.

Liver function tests will assess the patient's liver enzyme levels, including AST, ALT, and bilirubin, which are typically elevated in cases of liver injury. A liver ultrasound will provide detailed images of the liver, helping to identify any structural abnormalities, such as lacerations or hematomas, that may be causing the patient's symptoms.

**Why Each Wrong Option is Incorrect**
**Option A:** Abdominal CT scan without contrast is not the best initial test in this scenario as it may not provide sufficient information about liver function or identify structural abnormalities.

**Option B:** Chest X-ray is normal, and the patient's symptoms are localized to the abdominal region, making this an unnecessary test.

**Option C:** Ultrasound of the gallbladder may be useful in diagnosing gallbladder disease, but it is not the best initial test for evaluating liver dysfunction and potential complications in this postpartum patient.

**Clinical Pearl / High-Yield Fact**
In cases of postpartum liver injury, it is essential to consider the possibility of liver laceration or infarction, which can be life-threatening. A prompt diagnosis and management of these complications are crucial to prevent long-term liver damage or even mortality.

**Correct Answer: D. Liver function tests (LFTs) with liver ultrasound.**

✓ Correct Answer: C. Ultrasound of the right upper quadrant