My Mom Has Neropthey And Is On Some Medication For

my mom has neropthey and is on some medication for it and just on the last 2 weeks of being on pure oxygen from her pneumonia she is having black dirahea every couple days its fine then she get it back is on alprazolam 1mg and hydrocolacetam 325 mgs but only takes a half pill of it 3 times a day and lyrica 100 mg what is causing her diarrehea be so yucky looking