It is narrated from Hazrat Aisha (may Allah be pleased with her) that when the Prophet (peace and blessings be upon him) would come out of the toilet, he would perform ablution.
Hadith Referenceمسند احمد / مسند النساء / 25561
Hadith Gradingحکم دارالسلام:حديث صحيح، وهذا إسناد ضعيف لضعف جابر