I just delt with this problem from my 10 year old son. He was so impacted that the hospital kept him for 3 days to get him cleaned out (it was so bad the enama didn't work). Anyway, there is an a name for it........encopresis. For my child, his colon was so stretched out he had to go back to pullups because he lost sensation for about 5 months but just recently regained his sensation. Also, like your grand-daughter, my son also became very irratable and moody. It is very common to get a bacterial overgrowth after going through this so we had to give him stuff to kill the bacteria and also started to give him a lot of probiotics. Culturell is very good for this problem and also giving garlic capsules. Also, to you might want to get her some Oxypowder . It's like an oral emema...........it will disolve impaction and keep her very regular. I was uncomfortable with giving my son the prescription laxative the doctors gave him and stool softeners and found Oxypowder to work great if he gets backed up. Also, giving about 500mg of magnisum and 2000 mg. of vitamin c powder daily will keep things moving.