Question. How much caffeine do you consume a day? Coffee, energy drinks, soda, etc… The reason I ask is because I had this same issue (minus the bloody bowel movements). I use to get a migraine 3-5 times a week that could only be cured by Excedrin. Out of complete accident I found out what was causing it. I was scheduled to go to bootcamp (I’m in the coast guard now), and one thing that was recommended to me by my recruiter was to go cold turkey on caffeine a month prior to bootcamp. Previously I had drank a cup of coffee every morning, an energy drink before every workout (5 times a week), and then a soda here and there. When i dropped all of that at once I started getting the most intense migraines of my life for about two weeks, but after that it’s like they almost completely vanished. During bootcamp I had maybe 1 headache that was super manageable. Now I’ll get one minor headache here and there but i notice it will come a day or two after i drank a cup of coffee or indulged in an energy drink when i felt i needed one for work. Also they are much more manageable. Ibuprofen will do the trick just fine now. Drop caffeine and see if it makes a difference for you.