Edmonds-Karp Algorithm with both directed and undirected edges? How would this work and be implemented?

If you have directed edges pointing away from the source to a bunch of other verticies, and directed edges pointing from those vertices to a sink, but have those vertices in the middle linked by undirected edges, how would flow work and be maximized?
Replace each undirected edge $(u,v)$ by two directed edges, one in each direction: $u\to v$ and $v\to u$.  That gives you a graph with only directed edges.  Then the max-flow on that graph is the same as the max-flow on your original graph.