I get splitting headache whenever I'm constipated and the headache is always accompanied by acidity and gas. The headache gets worse as I sit or lie down, throbbing with every pulse. The situation doesn't arise if I'm on a regular diet and my daily routine is not broken. But whenever I have to break my eating/sleeping routine, I land on this headache. What precautions can I take to avoid this? What first aid should I get in case I do get a stomach related headache?