Stomach bloating after lunch is often caused by swallowed air, rapid eating, or specific food triggers. For immediate relief from gas, you can try over-the-counter Simethicone (such as Gas-X) after your meal. If your lunch commonly contains dairy or complex carbohydrates (like beans or broccoli), enzyme supplements like lactase or alpha-galactosidase (Beano) taken right before eating can help. Additionally, try eating more slowly and avoiding carbonated drinks. Please consult a healthcare professional if your bloating is chronic, severe, or accompanied by warning signs like unexplained weight loss, severe pain, or changes in bowel habits.