Hi and welcome to the Migraines & Headaches Community.
You need to see your PCP for follow ups. They should have told you that at the ER.
Try taking some Magnesium Citrate to help with BM and headache.
Also to help with BM...a combination of Miralax and Milk of Magnesia (which is also a different form of magnesium)
Milk of mag is the mover, Miralax is only a softener.
Drink lots of water