Tequila, Lots of it.
Whiskey as a backup
I had an unpleasant run-in with that disgusting bug this summer as the heat fermented the skykomish. I lost 10-15 lbs too and was knocked way out for a week or two.
Doc tested me, confirmed it, and gave me the prescription for flagel. However I never took it since by that time I finally felt like I was on the mend. I don't think he would have given the prescription without the test though. Unfortunately from my understanding, the fix is about as bad as the bug. It really nukes your interior of good and bad bugs. Typical normal course of the bug is like 6 weeks - so if you can ride it out, try.
This is gross, but don't eat any greasy stuff - the bug stops the GI from digesting the oils, and well, you'll smell the result.
An old paddler girlfriend had it and tried everything to knock the bug for weeks - western med, holistic, diet stuff - nothing worked. Finally, she got sloshed on tequila one night and the bug was done. I swear I felt better after a stiff whiskey this summer.
If you need an excuse to drink the bug away - it's the 12 bars of Xmas saturday night in Fremont!!