$re = '/.*Treatments|Physical examination.*|[^P]*?\b([A-Z]{2,})\b/ms';
$str = 'Suspendisse potenti:
Not MATCHED here. Por TOG esfet.
Treatments:
Pellentesque eget sollicitudin quam, id venenatis odio. Nam non tortor elit. Pras ultricies est urna, eu feugiat purus tempor a. Donec IBUPROFEN feugiat tristique ante, eget vulputate velit rhoncus ut. Morbi MATCHED HERE elementum leo a vulputate cursus. Sed at purus sit amet sapien COLCHICINE ullamcorper convallis.
Physical examination:
Also NOT MATCHED here at TO pulvinar mi, at vehicula libero. Nunc semper, neque sed tempor iaculis, nunc diam egestas lacus, Peget sodales sapien orci eget leo.';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php