如何在RSS上显示帖子ID？

这是我的代码：

$rss = new DOMDocument();
$rss->load(\'https://www.ciusan.com/feed\');
    $feed = array();
    foreach ($rss->getElementsByTagName(\'item\') as $node) {
        $item = array ( 
            \'title\' => $node->getElementsByTagName(\'title\')->item(0)->nodeValue,
//          \'desc\' => $node->getElementsByTagName(\'description\')->item(0)->nodeValue,
            \'link\' => $node->getElementsByTagName(\'link\')->item(0)->nodeValue,
            \'date\' => $node->getElementsByTagName(\'pubDate\')->item(0)->nodeValue,
        );
        array_push($feed, $item);
    }
    $limit = 5;
    echo \'<div>\';
    echo \'<ul class="soo-latest">\';
    for($x=0;$x<$limit;$x++) {
        $title = str_replace(\' & \', \' &amp; \', $feed[$x][\'title\']);
        $link = $feed[$x][\'link\'];
//      $description = $feed[$x][\'desc\'];
        $date = date(\'l F d, Y\', strtotime($feed[$x][\'date\']));
        echo \'<li>&raquo; <a target="_blank" class="soo-info" href="\'.$link.\'">\'.$title.\'</a>\';
        echo \'<small class="help">Posted on \'.$date.\'</small></li>\';
//      echo \'<p>\'.$description.\'</p>\';
    }
    echo \'</ul>\';
    echo \'</div>\';

/%category%/%post_id%/%postname%/

echo \'<li>&raquo; <a target="_blank" class="soo-info" href="\'.$link.\'">\'.$title.\'</a>\';