Constipation, headache and excessive flatulence, could simply be because of a low water intake and low fibre in diet. Your endoscopy report is also normal, which suggests that you are not suffering from any upper gastrointestinal issue. Try the following: - Drink atleast 3 litres of water daily. - Go for a walk daily, for atleast 30 minutes. - Eat regular meals, avoid excessive oily/ sweet foods. - take 1 tablespoon of Naturalax / Fibogel powder in a big glass of water at bedtime, daily. If your discomfort persists, visit an abdominal/ general surgeon and get evaluated.