I came across some Nutrigen Inulin sachets for stool regularity on Holland & Barretts website and they *seem* to be making a difference. My three year old has been struggling with stool withholding for about a year now. Longest he held was 10 days and his stools (when they did appear) were a big sticky lump (in nappy) rather than a formed shape, with lots of crying and shouting to get the job done. Lactulose just seemed to make the problem worse. Add to that he still boobs for England and is a picky eater, he was generally only going once a week at best, with the 2 days before just wanting to snuggle under the duvet and not do much.
The poo app actually made him worse "oh no a poo is coming - hide!" - great
Anyway, since these sachets he poos when he feels he needs to (with only a little bit of snuggling up before hand), there is no crying and I can see that they are becoming a formed shape. We're now down to a four day interval!!
I haven't seen them mentioned on here before - maybe they can help someone else?