Wierd, Messy, Foul Smelling, Poop After Months of Normal Poops - HELP!

[Guest guest]

Jack (my ASD son just turned 3) had an MRI and sedated hearing test

2 days ago. They gassed him to sleep. He did awesome and woke up

fine, walked, ate, drank, and had dinner once home. All was pretty

normal. Also, he's been strict GFCF, yeast and sugar free for

months now. He's also been treated for bacteria and yeast and his

poops have been BEAUTIFUL (for lack of a better word). Since

the MRI, he did not poop yesterday at all but was super gassy and

seemed uncomfortable. Last night he kept laying down on his tummy

and then standing up posturing like he needed to go poop but never

did. We gave him a salt bath last night and he went right to bed

which is kind of strange. This morning before leaving for school,

he had a poop and it was a flashback to the old days of the horrid,

messy, foul smelling, mucousy, light colored, frothy, just plain

WIERD poops! I took him to school and warned his teacher. He was

acting spacey and drugged out all the way to school though.

My question is 1)Why all of a sudden after having predicable,

formed, normal poops did he have this setback?

2)Could this be some kind of " die-off " from the gas used during his

MRI?

I am beyond frustrated b/c I felt we had made so much progress

regarding his GI issues. I have no idea if I've done something

wrong, if something isn't working anymore? I'm at a complete loss

and feeling defeated. HELP!

Carla