**Question:** An 88-year-old white woman with osteoarthritis has noticed mild epigastric discomfort for several weeks. Naproxen has helped her joint symptoms. She has emesis that resembles coffee grounds on three occasions. Select the most likely cause of gastrointestinal blood loss

A. Gastroesophageal reflux disease
B. Peptic ulcer disease
C. Gastritis
D. Gastrointestinal malignancy

**Core Concept:** Gastrointestinal blood loss can be caused by various pathological conditions. In this case, the patient presents with joint symptoms improved by naproxen, which is a non-steroidal anti-inflammatory drug (NSAID) targeting COX enzymes. Naproxen's effectiveness in managing joint symptoms suggests that the gastrointestinal blood loss is likely due to NSAID-induced gastropathy.

**Why the Correct Answer is Right:**

D. Gastrointestinal malignancy is a possibility, but the patient's response to naproxen therapy makes it less likely as it would not help manage her joint symptoms.

A. Gastroesophageal reflux disease (GERD) is a common cause of upper gastrointestinal bleeding, but the emesis resembling coffee grounds suggests a more severe condition.

B. Peptic ulcer disease is another possibility, but the patient's response to naproxen makes it less likely.

C. Gastritis is a broad term, but the emesis resembling coffee grounds and the patient's response to naproxen make it less likely.

**Why Each Wrong Option is Incorrect:**

A. GERD is a common cause of upper gastrointestinal bleeding. However, the emesis resembling coffee grounds indicates more severe bleeding, which is more consistent with peptic ulcer disease or gastrointestinal malignancy.

B. Peptic ulcer disease is a known cause of upper gastrointestinal bleeding, but the patient's response to naproxen makes it less likely.

C. Gastritis is a broad term that includes various causes, but the severe emesis resembling coffee grounds and the patient's response to naproxen make it less likely.

**Clinical Pearl:**

In older patients with gastrointestinal blood loss, it is essential to consider the possibility of gastrointestinal malignancy despite their response to NSAID therapy. The emesis resembling coffee grounds indicates severe bleeding, which is more consistent with peptic ulcer disease or gastrointestinal malignancy. Further evaluation, including endoscopy, is recommended.