Warning: XSLTProcessor::transformToXml() [xsltprocessor.transformtoxml]: I/O warning : failed to load external entity "file:////srv/scielo/www/bases/xml/cir/v63/1561-2945-cir-63-e1601.xml" in /srv-new/scielo/www/htdocs/class.XSLTransformerPHP5.php on line 36 Ácidos biliares y esófago de Barrett