For support with toileting you can get support from ERIC The Children's Bladder and Bowel Charity.

You can call the free helpline: 0808 169 9949 Mon to Thur, 10am - 2pm or visit the website ERIC - https://eric.org.uk/

The website includes information and advice on:

• Children's Bowels - Constipation, Soiling, Stool Withholding and Baby and Toddler Poo. 
• Child's Bladders - Bedwetting and Wee Withholding.
• Potty Training
• Toilet Anxiety
• School Toilets

The NHS have produced the 'Poo Goes Home To Pooland' resource. Originally developed by Tamsin Black as a colouring book for children with encopresis. Designed to suit the cognitive development stage of children up to around seven years of age. Illustrations and text are intended to promote understanding of toileting matters and to relieve anxiety.

It is also available as a FREE App.           

Android app (free download on the Play store)
play.google.com/store/apps/details?id=uk.nhs.ntw.poogoestopooland

iOS App (free download on iTunes)
itunes.apple.com/gb/app/poo-goes-home-to-pooland/id987924591