Sayyidah Aishah (may Allah be pleased with her) narrates that one of his (peace and blessings be upon him) wives performed i'tikaf while in a state of istihadah (irregular bleeding). She would see yellowness and redness. Sayyidah Aishah (may Allah be pleased with her) said: Sometimes we would place a basin beneath her while she was praying.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8602