I had 4 obstructions in the first 3 months after takedown. None in the 26 years since. It takes a while for the swelling from surgery to go down. The first was an Ileus right after takedown, the other 3 were food obstructions caused by swelling and adhesions. It’s just postsurgical nastiness that dies down.
I would suggest going easy on the pain meds and eating real soft foods for a while. No raw carrots. No overeating even if you feel hungry and great. Lay off anything that will slow the bowels down. Walk a ton (this promotes peristalsis) and drink plenty of liquids. These are all common sense self help steps. Give it another 3 months or so and you should be out of the woods so to speak. For now lots of walking. Get on a treadmill and do at least 30 minutes at a solid pace of like 3.5 mph. Don’t lay around and pop pain pills- do that and you are practically begging for another one.
Regarding the headache- are they withdrawing you off Prednisone? I got weaned off and had a dull headache that was virtually continual for a couple of months. Withdrawal headaches.