Hi Torn
The DWP is working with a backlog of cases - so it is impossible to give you an accurate time frame but most people waiting for a change of circumstances are waiting at least four months sometimes longer. (Of course, there is the odd one or two who hear more quickly, but that is not the norm at the moment)
What's the likelihood of a medical assessment? It is more likely than not, but sometimes they make a decision on what has been sent in.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems