There Is An Awful Bitter Taste In Mouth. Have Had

There is an awful bitter taste in mouth. Have had colonoscopy, throat scope, blood work normal, gallbladder is fine, tested thyroid, liver, kidneys and celtic disease tested for and negative, continue to have bitter taste and no appetite because food doesn't have taste. Lost 65 pounds after pregnancy. Doctor's last effort was to take probiotics for 3 weeks. Still continue with bitter taste and no appetite.