Is the husband's return to his wife, whom he divorced with the second divorce, valid when the return occurred during the woman's third menstrual period? And does the woman have the right to refuse to return to her husband due to his abuse of her and his engaging in anal intercourse with her?

A woman who has been revocably divorced can be taken back by her husband as long as she is within her waiting period ('iddah), which is three menstrual cycles. His taking her back is valid even during the third menstrual cycle. As for a husband engaging in anal intercourse with his wife, this is one of the major sins (kaba'ir). The wife must prevent it, and if she complies, she is sinful. If it becomes a habit, they must be separated. If the husband insists on forcing her into this forbidden act, she has the right to seek divorce, and she should refer the matter to the Sharia courts to compel him to desist or to grant her a divorce from him.