To help relieve your symptoms, you can consider these common over-the-counter generic options: 1. For constipation: An osmotic laxative like polyethylene glycol or a stool softener like docusate sodium will gently help restore regular bowel movements. 2. For gas: Simethicone is highly effective at breaking up gas bubbles in your digestive tract. 3. For your headache: Acetaminophen is a safe pain reliever that will not irritate your stomach. Dehydration often links headaches and constipation, so please drink plenty of water. If your symptoms do not improve, or if you experience severe abdominal pain, vomiting, or fever, please consult a doctor. Rest well!