The World Federation One Stop Fiqh

Ruling 1552

If a fasting person who is aware of the fact that he is fasting intentionally eats or drinks something, his fast becomes invalid, irrespective of whether the thing he ate or drank was something normal – such as bread and water – or not – such as earth and the sap of a tree – and irrespective of whether it was a little or a lot. In fact, even if one takes a toothbrush out of his mouth and then puts it back into his mouth and swallows the moisture, his fast becomes invalid unless the moisture of the toothbrush becomes obliterated in his saliva in a way that it can no longer be regarded as external moisture