I had a smaller dose of this back in 2009, fusion of L5S1 and for a few days after the surgery I thought that I was going to die, the pain was tremendous. The first six weeks was the worst of it. One of the worst things was trying to take a dump, you don't realize the pressure you put on your back muscles until they have been pulled away from your spine and put back during surgery. Getting the staples removed later was fun too. Before the surgery the disc between L5 and S1 had practically disintegrated and the joint debris and osteophytes was really grating on the nerves so that area was already inflammed. It took a while to heal but afterwards no more trouble from that joint again. It's hard to imagine having so much done as you have. They may have recommended a high protein diet to help facilitate healing, which might lead to constipation, already a potential problem with pain meds. You might have to use some laxatives, better than having to squeeze after getting cut up!