What would cause constant yellow diarrhea with acid refux, nausea for 1 month

[Mad5332]

I was on augmentinew 6 weeks ago and had mild diarrhea, I also have Gerd and traveled to Mexico after my augmenting treatment. Upon return diarrhea has been chronic along with acid reflux, nausea, stomach cramps, weightloss of 7 lbs and loss of appetite with fatigue. Dr put me on metronidazole but could only take 3 pills . Had to stop due to severe side effects. Diarrhea is yellow and I am on a brat diet for 3 days now. No improvement.any ideas would be greatly appreciated.