advice needed

Hi Everyone I haven't been on here much lately, But I was wondering if I could get some advice I have a Two Year Old Filly and she has Chronic Diarrhea, It started when I sent her and her dam to an outside stallion they receieved Excellent Care. But I think Something must have made her Stomach...

I had another still born foal today. Anybody have any ideas what may be causing this. Neither on was a red bad, both normal delivery, both full term. First was a sorrel stud, second was a black filly. HELP