Someone asked Hazrat Amirul Momineen, Khalifatul-Masih V^(aba) whether it was necessary to perform istinja’ when renewing wudu upon having passed wind. Huzoor-e-Anwar^(aba), in his letter dated 22 July 2021, provided the following reply to this question:

“There is no mention of doing istinja’ before wudu anywhere in the lived example of the Holy Prophet^(sa) nor in his statements wherein he has described the details of wudu. Therefore, if one’s wudu is invalidated due to having passed wind, there is no need to perform istinja’ before renewing the wudu for salat. However, if any faecal matter or urine have also been discharged with it, then it becomes necessary to perform istinja’ before wudu so that any impurity can be washed first. Otherwise, if one has done istinja’ once after relieving themselves and performed wudu, then it is not necessary to perform istinja’ again after passing wind in order to renew the wudu.”