Hello, 

It must be tough on your partner too being away from you and the kids for so long. But he knows he can't leave his Mum as she doesn't have long left and would feel guilty leaving her. The only support you can give your partner is being the listening ear at the other end of the phone. Just let him know you love him and your here for him at this sad time when he's about to lose his mum. You can give him more support once he's back home with you and the family. To me it sounds like she really doesn't have long at all so these next few days to maybe a week or so are going to be extremely important. 

My Dad passed away in August. I think it was about a week or so after a syringe driver was fitted. He stopped eating and found it hard to swallow liquids. Then he went into a deep sleep. He slept all the way through Monday, Tuesday and Wednesday. The Wednesday evening he died. Despite the lack of response, hearing is apparently the last thing to go when someone is dying. So it is important for him to carry on talking to his mum and hold her hand so she knows she isn't alone. 

Yes it is possible that after a short stay in the hospice she may be allowed home. This will give her some respite meaning your partner will get a little break whilst they adjust any medication and try and make her comfortable and pain free. If she hasn't been eating then that will also contribute to the constipation. Hopefully they can sort it out and maybe your partner will get a better insight into what is to be expected in upcoming days/weeks etc. If they allow her home then I would assume she is well enough unless it is noted that she wants to die at home then they won't bother keeping her in.