washing machine plumbing question ?

24 Hour Plumbing Services https://bitly.com/324IIJN

im in uk ..we use a 4" pipe for toilet ..your very similar ..we can buy a reducer ..4" to 2" .50mm ..then use a reducer from 2" 50mm to 40mm ..our standard waste  for washing machine ..you then connect this to a washing machine trap ...simple fix 

yes, there are issues ... washing machine requires an open connection from the discharge to the waste pipe -- BUT there is no trap under the old toilet connection [trap is built into toilets], so you have to add one.  This is probably job for handyman or plumber ... and, there is no harm asking at your hardware store after the parts required.  take photo and explain, patiently, what you are trying to do  -- grampa

Don't know exactly what you have, but you could connect to the commode flange in the plumbing at the floor with a new wax ring and a second commode flange turned upside down and bolted together.  Then, from that new end of the second commode flange build a pipe riser for the washing machine drain hose connection.  That riser will have to include a P trap to hold water to prevent sewer gas from escaping into the room. 

that is a question for your plumber, but I would think so ................