I Am Taking Care Of An Elderly Lady Who Has

I am taking care of an elderly lady who has a problem with losing some of her food or drink after meals. its not quiet a vomiting. Its like she burps holds her head forward and spits it up, its not digested. sometimes its phleam. Phenagran, mild dose, hasn't helped. Her bloodwork was ok, showing a uti, but has finished her meds for that. What could be causing this?