A 10-year-old boy has complained for 1 month of intermittent epigastric pain that awakens him from sleep. He notes that eating food sometimes helps. He reports black stools during the prior week, and also admits that he has occasionally vomited frank blood. choose the best initial diagnostic step in the evaluation of the patient’s apparent GI hemorrhage.

**Core Concept**
The patient's presentation of intermittent epigastric pain, black stools, and hematemesis (vomiting blood) suggests a gastrointestinal (GI) hemorrhage, likely from a bleeding peptic ulcer. This condition requires prompt evaluation and management to prevent complications.

**Why the Correct Answer is Right**
The initial diagnostic step in evaluating a patient with suspected GI hemorrhage involves stabilizing the patient and obtaining a thorough history, followed by endoscopy to identify the source of bleeding. The correct answer, **Option B: Upper GI endoscopy**, allows for direct visualization of the upper GI tract, including the stomach and duodenum, to identify and treat the source of bleeding. This minimally invasive procedure can also provide tissue samples for histopathological examination to determine the cause of bleeding.

**Why Each Wrong Option is Incorrect**
**Option A:** Blood tests, including complete blood count (CBC) and coagulation studies, may be helpful in assessing the severity of blood loss but are not the initial diagnostic step in evaluating a GI hemorrhage. They do not directly identify the source of bleeding.
**Option C:** A plain abdominal X-ray may show signs of free air or a nasogastric tube in the abdominal cavity, indicating a perforated ulcer, but it is not the initial diagnostic step in evaluating a GI hemorrhage.
**Option D:** A CT scan of the abdomen may be helpful in identifying complications of GI bleeding, such as a pseudoaneurysm or a large hematoma, but it is not the initial diagnostic step in evaluating a GI hemorrhage.

**Clinical Pearl / High-Yield Fact**
In cases of suspected GI hemorrhage, it is essential to remember that the "triple threat" of peptic ulcer disease includes pain, bleeding, and perforation.

**Correct Answer:** B. Upper GI endoscopy.

✓ Correct Answer: B. Fiberoptic endoscopy