[Paul M]

I dont see what relevance pagetext being mediumtext is, php does not care (nor does vbulletin, and and its always been that type anyway).

I run the query and it gives me output if the pagetext not mediumtext type

What you mean by this, run the query how ?
I dont believe you are running this query direct on the server, and changing the column type (and to what would you change it anyway).

The code you posted above isnt in the file you attached, though some similar looking code is.

Have you done any debugging to print $section directly after the start of the While loop ?
I seriously doubt pagetext is actually empty, more likely all the functions you are running it through are doing something.