Sick blue gourami

As shown in the pic, one side of my blue gourami has unusual dark discoloration. The other side looks normal.
It does not eat much and sits on the bottom of the tank alot. It also has white/clear stringy poop.
Please help me figure out what wrong with it and what to do. Thanks.

Hi

Can you give us more information?
Tank size
Water temp
Is the tank cycled
How often do you change water
What chemicals do you use
Water parameters, Ph KH Gh
What do you feed him and how much

If the water quality is not the best, it could easily mess with your gourami's coloration. I haven't really seen this with my fish, but perhaps it is ammonia burn? As Nick said, it helps to know your water readings so we can give better advice. Most illnesses are caused by low water quality and can be fixed/avoided with regular water changes. This goes for the white poo as well. It sounds to me like you have a few different issues going on.

So then, how long has the tank been up and running? What other tank mates are there and what size tank is it? If you could do a water test with test strips or by taking it to a pet store, it would help quite a bit.