Pain in the throat and a bitter taste in the mouth can be signs of an underlying infection, such as a throat infection or tonsillitis. It is also possible that the symptoms are due to other causes, such as acid reflux or allergies. If you experience this symptom on a regular basis, it would be best to consult with your doctor for a proper diagnosis and treatment plan. Your doctor may suggest further tests, such as blood tests, throat swabs, or imaging tests, to determine the cause of your symptoms.