Hi, Detached house about 4 years old. Shower in ensuite bathroom started to give problems draining last week, happens every 3rd or 4th time shower is used. Noticed that when flushing ensuite toilet you can now hear a whooshing gurgling sound from shower drain. Below the ensuite, on the ground floor is the downstairs toilet. This is now not flushing correctly, water fills the bowl when flushed. Main toilet to back of house is unaffected. Have tried using plunger and drain clearer on sinks and shower. Also tried pouring hot water downstairs toilet with washing up liquid. I am assuming the ensuite and downstairs toilet are using the same pipe. Is there anything else I can try or do I need professional help? Thanks