How about something like...

my $joiner = $select_any ? ' or ' : ' and ';
my $where = join $joiner, ('bodytext like ?') x @terms;
$where .= " order by id desc";
my @terms = map { "%$_%" } @terms;

my $sth = $db->prepare("$querystr $where");
$query->execute(@terms);
[download]

Insert comments and error handling, and this should be much cleaner.

Disclaimer: my SQL-fu is weak, too :-)