Brief Answer: Food Poisoin or AGE. Water, Electral, Antibiotics Detailed Answer: Hello, Thanks for your query. I have gone through your query and understand your concern. I suspect all the symptoms are due to food poisoning or Acute Gastroenteritis (AGE). Food poisoning or Acute Gastroenteritis (AGE) usually cause loose stools. This result in loss of plenty of fluids from body. This ends up in dehydration due to less body fluids. This cause Dehydration headache and Heart Palpitations due to water and electrolyte loss in body. Please follow the following measures. 1. Drink plenty of fluids. 2. Have Electral powder or drink and drink often. 3. You may need broad spectrum antibiotics like Ciprofloxacin as well as Metronidazole. 4. Wash you hands regularly before food and after using toilet. 5. Eat well cooked food always. 6. wash Vegetables and meat in under running water. Hope this helps. Wishing you good health.