It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) was asked about the woman with istihadah (irregular bleeding), and he (peace and blessings be upon him) said: "That is a kick from Satan in her womb."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11508