Anal sex

A mere innocent question: What's wrong with anal sex?? What's the big religious taboo?? As long as it is consensual as all sex and all affairs should be, what's wrong with it? Is it because children are not conceived that way?? All the more reason to be favored, I think all couples in countries with population inflation problems like Egypt should lawfully be asked to do it this way, if they don't already do it east west north and south, "fel kabatha"