That can be pretty complicated as DTV is wired completely differently than Comcast. DTV also typically disconnects Comcast outside. I'd recommend a tech visit.
Yes, the wires inside are the same. Comcast may have physically disconnected your home -- so when they say they reconnected, they may have just done so at the pole. Typically you would need a tech to connect your outlets (including internet) correctly. If you want to try on your own... Comcast mainline-->2-way splitter-->one port feeds the modem, other port feeds another splitter that feeds everything else.