Abdominal pain and other symptoms consistent with probable ulcer -- but tests ruled out ulcer, gallstones, celiac and anything else they could see in an endoscopy.
Diagnosed two weeks ago with C. diff infection -- unusual in someone my age, but it's becoming more common. I'm assuming I picked it up in Scotland, but could have gotten anywhere along the way in transit as well.
The bug's like MRSA, becoming multi-drug resistant. Ten days of Flagyl killed it, restored my energy levels, and I'm now taking several probiotics to get my GI system back online. Still having enough stomach pain not to be able to run or even jog, but I hope that will subside over time.