IMPORTANT!!!
You're in serious trouble.
I've had an impacted colon....it's not pleasant.
Your standard diet must be neglecting either regular fiber, water, and/or both.
To fix your problem, plan on 86ing your diet for a day or so. Get some fiber, foods that are gentle on your digestive system, and at least 2 bottles of MAGNESIUM CITRATE.
In short, since stuff will flush thorugh you, you don't wan't to bother eating stuff that takes time to digest.
Take a bottle of magnesium citrate and drink it all. Also drink pleanty of water. It's a saline laxative, and it will promote a lot of junk breaking loose from your intestinal walls and being shot out the body. You will have loose movements, so plan on spending the day home. Your movements likely will be painful if some of the discharge is hardened from being in the body for a long time.
Don't eat anything until a good couple of hours after you take the magnesium citrate so it doesn't just get flushed through with everything else.
After you get done pooping your brains out, see if your stool is normal sized. One treatment should flush a lot of stuff loose...if not all of it.
However, I'd suggest repeating the process the next day. Remember, lots of liquids.
If you want to make movements less painful, take the magnesium citrate before bed (assuming you'll wake up if you feel the need to go bathroom). I find that being horizontal lets the laxative work overnight (gravity isn't your enemy), and first thing in the morning, you'll need to go, but it won't be so harsh because any stomach acid flushed into your intestines will have had time to neutralize.