I disagree - settling ability or inability is not specifically related to the need for solids. There are many developmental changes that can result in changes to sleeping.

Please consider alternatives to manage constipation before resorting to medicated treatments which may have a long term impact on bowel function. Have you considered BLS as an alternative to puree??
I haven't really looked into BLS but maybe it's something i should be looking into a little more As i said i opted not to go for the coloxyl but thanks for your bringing to my attention the long term impact it could have on my DS if i had chosen to use it as a long term solution.