<?php
$re = '~(8768|9875|2353).*(?:\R(?!\R).*)*~iu';
$str = '8768 text text
text
868123
text
text
text.text
9875 text
text
2353
text
text';
$subst = '';
echo "The result of the substitution is ".$result;
PD9waHAKCiRyZSA9ICd+KDg3Njh8OTg3NXwyMzUzKS4qKD86XFIoPyFcUikuKikqfml1JzsKJHN0ciA9ICc4NzY4IHRleHQgdGV4dAp0ZXh0Cgo4NjgxMjMKdGV4dAp0ZXh0CnRleHQudGV4dAoKOTg3NSB0ZXh0IAp0ZXh0CgoyMzUzCnRleHQKdGV4dCc7CiRzdWJzdCA9ICcnOwoKJHJlc3VsdCA9IHByZWdfcmVwbGFjZSgkcmUsICRzdWJzdCwgJHN0cik7CgplY2hvICJUaGUgcmVzdWx0IG9mIHRoZSBzdWJzdGl0dXRpb24gaXMgIi4kcmVzdWx0Ow==