Since this is someone you know and not you, can you at least share what condition this was? If it's something truly rare in the place you live (say, tropical sprue) then it may be a difficult diagnosis that gets misdiagnosed as something more common because of the following approximation:

  var i = 0;
  while(patient==ill){
    if(hoofbeats){
       if(i<20){
         return horses;
       }else{
         return `hunt zebras`
       }
       i++;
    }
  }