For acidity and gas, over-the-counter antacids or H2 blockers (like famotidine) can provide temporary relief, while simethicone helps ease bloating. However, experiencing both upper and lower abdominal pain could indicate conditions ranging from severe indigestion and IBS to infections. Because lower abdominal pain requires careful evaluation to rule out serious issues like appendicitis, I strongly advise against self-medicating with strong painkillers, which can mask symptoms. Please consult a doctor for a proper diagnosis and tailored prescription. Seek immediate emergency care if you develop severe pain, fever, persistent vomiting, or blood in your stool.