I would have said that Pie was a lot better - we'd had a couple of days with no symptoms, and this afternoon and early evening he looked great - bright, alert, friendly and pretty much back to normal. He'd been passing a lot of manure and everything seems fine. But then about an hour after feeding time this evening, he went down in his stall again, switching from sternal to flat and back and forth, and groaning, and passing large amounts of gas. I went in his stall and held his head for a bit, then he got up and was pretty much back to normal - alert and interactive - although a bit touchy about his left side. This wasn't as bad as his attack last Wednesday, but was as bad as how he was feeling a day or two after that.
This is the pattern - brief episodes of sharp abdominal pain, about 45 minutes to an hour after p.m. feeding, accompanied by lots of gas. The elevated liver enzymes, particularly GGT, suggest bile duct involvement - either inflammation or a partial obstruction by a bile duct stone, and this would fit with the timing after feeding time. But it's really hard to tell what's going on. He has days where he feels better and days where he doesn't, despite having been on antibiotics and anti-inflammatories for a week. He doesn't seem to have symptoms any other time of day.
The vet is coming Wednesday to do another blood draw to see if anything's changed. If things aren't moving in the right direction, I may trailer him to a vet clinic - we have a couple of good ones to choose from - to have a liver ultrasound and any other tests they may recommend.
I keep thinking that things are getting better and then they aren't - it's frustrating to see my horse in pain and not be able to fix it.