I have 2 columns in basement that have recently been redone. I had no idea there was a main pipe there until once they had recovered the column back and I could hear the water rush down. I was told it's because they made that post/column smaller in width. I don't believe that this could cause the pipe to sound as if there is nothing surrounding it.
My question is if there is any type of insulation or something else, that can stop the sounds of rushing water from being heard?

Is this your main plumbing stack? All interior drains go down a stack.

Is this your main plumbing stack? All interior drains go down a stack.

It's a large black pipe. It operates drains from upstairs bathroom toilet, shower, and washer.

Is it plastis or cast iron, betting plastic.

Is it plastis or cast iron, betting plastic.

Plastic

You could try,

Soundproofing a Drain Pipe With Insulation | Home Guides | SF Gate (http://homeguides.sfgate.com/soundproofing-drain-pipe-insulation-81944.html)

Or

How to Muffle Water Pipes Within a Wall | Home Guides | SF Gate (http://homeguides.sfgate.com/muffle-water-pipes-within-wall-80430.html)

And you may get some ideas from here,

Acoustic Panels, Sound Deadening, Soundproofing Materials for Home and Work - Soundproof Cow (http://www.soundproofcow.com/)

And here,

Quieting Drainpipes | Plumbing | Plumbing, HVAC & Electrical | This Old House (http://www.thisoldhouse.com/toh/asktoh/question/0,,603768,00.html)