[My query is about train 52451]
In case you have postponed your trip, I shall still answer.
A few coaches of the Shivalik Deluxe Express have got western toilets, but if your are located in a coach that does not have one, you will have to wait for the train to stop, cross over to another coaches and then use the toilets (there are no vestibules).
But please don’t let this not make you feel uncomfortable. The train is very comfortable and the scenery is very beautiful.