Hi, you poor thing, it is so upsetting
we have had terrible time with poos. don't use suppositories, they are ok at pushing out but traumatic - make child associate poo with pain and you will get witholding - there are some great books. One is called something like Witholding and the child - but a very nice docotr who trained at Gt Ormond Street, will try to find a link
But the advice is right
(1) no milk - stops you drinking other things and is absorbed and discharged by kidneys so no help with "wetting" poo
(2) tons of water and clear fluids - you need to press your child to drink every 5 minutes or so, just a sip. it all helps
(3) as much wet food as possible. Neat orange juice (with meals) kiwi fruit no bran no bulking agent (you want ot reduce the poo!)
Lactulose is good - both softens and has sugar but be vey careful with dental hygience - give at meals
If worse to go GP and get Movicol Paediatrci - act now before you get full on witholding
also search function for some old threads on withholding - some great information and help that I got!
Good luck