Hi, Well, white stuff at the back of throat that comes off when gargling can be due to causes like Tonsil stones, if they are on the Tonsils while if it is not over tonsils and on the throat wall, then it can be probably yeast infection in throat. However the exact cause can be ruled out after through clinical examination. In case of Tonsil stones, it can be simply ruled out with clinical examination, however the other cause like yeast infection can also be ruled out but many a times a microscopic examination can help in ruling out what exactly it is. For now you can do warn saline gargles. Gargling with baking soda, you can dissolve half teaspoon in half glass warm water and gargle with it. Maintain a good oral hygiene and drink plenty of water. You should also get checked at the earliest as in case if it is yeast infection you can be advised anti fungal medication. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Honey Arora, Dentist