So I read it is possible..
"Pretty much the only thing that can cause things to go in reverse here is an obstruction in the bowel. An obstruction can either cause things to slowly pile up -- leaving a foot in the door, so to speak -- or can trigger a spasm in the muscles of the intestinal walls that forces the contents of the bowels back into the stomach.
Where things really start to get tricky is the underlying cause of the obstruction to begin with. It could be caused by a tumor, a twist or crimp in a section of the intestine, or compacted fecal matter from prolonged constipation that has caused a backup all the way to the opening of the stomach. "
I read it is serious issue and if not treated inmediatly you can die. I would think she will have to be closely monitored after getting the intestine unblocked. She will need to be on serious treatment against constipation. I read you can't go not pooping for more than 4 days.