What is the most likely diagnosis for a patient with a 3-month history of dull lower abdominal pain that worsens in the morning and improves after meals, without weight loss or abnormal bowel movements, and has a soft abdomen with moderate discomfort on palpation of the lower abdomen?

Duodenal Ulcer

The most likely diagnosis is duodenal ulcer (option e), based on the characteristic pattern of pain that worsens in the morning and is relieved after meals, combined with the absence of alarm features. 1

Clinical Reasoning

The symptom pattern strongly points toward duodenal ulcer rather than the other differential diagnoses:

Pain characteristics favoring duodenal ulcer:

• Pain relief with food intake is the hallmark feature of duodenal ulcer, distinguishing it from gastric ulcer where pain typically worsens with eating 1
• Morning pain (occurring between meals or when fasting) is characteristic of duodenal ulcer, as acid production continues without food buffering 1
• The dull, deep quality in the lower abdomen (epigastric region) aligns with peptic ulcer disease presentation 1

Why other diagnoses are less likely:

• Gastric carcinoma (option a): The absence of weight loss and the 3-month duration with stable symptoms make malignancy unlikely 2. Gastric cancer typically presents with progressive symptoms, anorexia, and weight loss 2

• Gastritis (option b): While gastritis can cause epigastric discomfort, it typically does not follow the characteristic pattern of pain relief with meals 3

• Gastric ulcer (option c): Pain from gastric ulcers characteristically worsens with food intake rather than improving, which contradicts this patient's presentation 1

• GERD (option d): The primary symptom of GERD is heartburn, not deep abdominal pain 3. The pain pattern described does not fit typical reflux symptoms 3

Diagnostic Approach

Essential next steps:

• Test for Helicobacter pylori using breath or stool testing, as H. pylori infection is a predominant cause of peptic ulcer disease in the United States 1, 2
• Assess for NSAID use, as this is the other major cause of peptic ulcer disease 1
• Consider endoscopy if the patient is older or has any alarm symptoms (though none are present currently) 2

Management strategy:

• If H. pylori positive: eradication therapy with antibiotics plus proton pump inhibitor for 4 weeks 1, 2
• If taking NSAIDs: discontinue use 1
• Initiate proton pump inhibitor therapy (e.g., omeprazole 20 mg once daily before meals) for 4-8 weeks 2

Important Caveats

The absence of alarm features (weight loss, abnormal bowel movements) and the relatively young presentation with stable symptoms over 3 months support a functional or benign organic cause rather than malignancy 2. However, if symptoms persist despite appropriate therapy, endoscopy should be performed to confirm the diagnosis and exclude complications 1.