Baby field mouse is constipated

Question
Hi, I found a baby field mouse 5 days ago & have been feeding him goats milk every 4 hours.  He was doing really well and has grown alot, this morning he has started to open his eyes.  However, this morning he seems distressed & his tummy is very swollen and he cannot seem to pass anything.  He also doesn't seem to have full use of his back legs (was fine at 1.30 this morning).  I have tried all the advice on stroking his bits with a warm cotton bud and rubbing his tummy but nothing is helping.  He is very hungry so I have given him a tiny amount of milk but have watered it down with water.  Can I give him anything to help? he's done so well to get this far.  Many thanks, Tracey

Answer
His back legs not working is a sign that there may be nerve damage
He needs immediate vet treatment for the possible intestinal problems
I am not a vet so I cannot give a proper diagnosis as can anyone on line. The animal has to be seen by a professional, certified veterinarian