Based on the location (left upper abdomen below the rib cage) and the description of a dull/sweet, gas-like pain, the common possibilities include gas-related discomfort, gastritis, acid peptic disease, or abdominal muscle strain. Since the pain is mild and not responding to simple antacids, it is less likely to be simple acidity alone. The picture does not suggest any visible swelling or acute surgical condition.
Next Steps
Start a proton pump inhibitor (e.g. pantoprazole / esomeprazole) once daily before breakfast for 5 days
• Use an antispasmodic/anti-gas medicine after food if bloating or gas sensation is present
• Take light meals and avoid spicy, oily, and junk food
• If pain persists beyond a few days or increases, get an USG abdomen done
Health Tips
Avoid alcohol, smoking, and late-night meals
• Do not ignore pain if it becomes severe, continuous, or is associated with fever, vomiting, or weight loss
• Persistent left-sided abdominal pain should be evaluated further to rule out gastric or splenic causes