It is narrated from Sayyida Aisha (may Allah be pleased with her) that the Messenger of Allah (peace and blessings be upon him) observed i'tikaf, and some of his wives also observed i'tikaf with him, even though they were experiencing istihada (non-menstrual bleeding) and blood was coming out, and because of the blood, they would place a basin underneath. Ikrimah said: Sayyida Aisha (may Allah be pleased with her) saw yellowish water and said: Such water used to come to so-and-so lady.
Hadith Takhrijاس روایت کی سند بالکل صحیح ہے۔ دیکھئے: [بخاري 309، 310، 2027] ، [مسند أحمد 131/6] ، [أبوداؤد 2476] ، [ابن ماجه 1780] ، [بيهقي 329/1]
Brief Explanation
(Commentary on Hadiths 898 to 902)
From this it is understood that a woman experiencing istihada (non-menstrual vaginal bleeding) can also perform i'tikaf (spiritual retreat), and yellowish discharge will not be an impediment to prayer, fasting, or i'tikaf.