Quick note. The word istibrāʾ carries two distinct procedures in Shia fiqh, both literally “seeking clarity.” The one a Shia woman cares about, and the one this entry covers, is the cotton-insertion check used to confirm that hayd or nifas has truly ended.
The two istibras
1. Istibra after urinating (men only). Per A. Sistani’s Islamic Laws, Ruling 69, this is a recommended (mustahabb) act men perform after urinating to confirm no urine remains in the urethra. Ruling 74 explicitly states there is no istibra for women after urinating.
2. Istibra of the menstruating woman (the cotton-insertion check). Per Ruling 495, if a woman’s bleeding stops before ten days and she suspects there may still be blood inside, she must either treat herself as still bleeding or perform istibra. A. Sistani’s text:
“Istibrāʾ here means she must insert some cotton inside the vagina and wait for a short while.”
If the cotton emerges fully clean, hayd has ended and she may perform ghusl al-hayd and resume worship. If any blood is present, hayd is still in progress. The same procedure applies to nifas (Ruling 506).
Why it matters
Acting on apparent dryness alone is risky. If a woman performs ghusl al-hayd based only on the visible absence of bleeding and bleeding then resumes within the 10-day hayd window, her status retroactively returns to hayd, which means the prayers she performed in between were void. Per Ruling 495, doing istibra (or treating herself as still in hayd) is required; refraining from worship without istibra is not permitted.
Practical
The exact protocol (when to perform it, how long to wait, what counts as a clean result) is one of the things the Tuhr app guides users through step by step, per their marja. For your own situation, follow your marja’s office.
Related
Source
A. Sistani, Islamic Laws (4th English edition), Ruling 495.
Primary sources
- A. Sistani · 495 Istibra of the menstruating woman (cotton-insertion check)
If a woman's bleeding stops before ten days and she deems it probable that there is blood inside, she must either perform ritual acts of worship as a precautionary measure or perform istibrāʾ; and it is not permitted for her to refrain from worshipping without performing istibrāʾ. Istibrāʾ here means she must insert some cotton inside the vagina and wait for a short while – and if her habit is such that her bleeding stops for a short while in the middle of ḥayḍ, as it has been said of some women, she must wait for a longer time – then, she must bring the cotton out. If it is clean, she must perform ghusl and perform her ritual acts of worship; and if it is not clean – even if it is stained with a yellow-coloured liquid – then, in the event that she does not have a habit of ḥayḍ, or her habit is ten days, or the days of her habit have not yet finished, she must wait. If her bleeding stops before ten days, she must perform ghusl; and if her bleeding stops on the tenth day or her bleeding lasts for more than ten days, she must perform ghusl on the tenth day. If her habit is less than ten days, then in case she knows that her bleeding will stop before the completion of ten days or on the tenth day, she must not perform ghusl.