What is the jurisprudential ruling on anal intercourse with one's wife (with whom the marriage contract has been concluded), and is this considered a valid consummation that entails the dowry and legal consequences?

The Hanbali school of thought—the one considered authoritative—holds that seclusion with the wife after a valid marriage contract takes the ruling of consummation, even if intercourse has not occurred. Thus, the full mahr becomes due, and the iddah (waiting period) becomes obligatory. This is the view of the Rightly Guided Caliphs, Zayd, Ibn Umar, and others. It is also one of the two earlier opinions of Al-Shafi'i.