Thanks for the new photos - those help quite a bit. I see two things going on - those bigger, diffuse body spots that seem to be coming up from under the scales, that doesn't look like ich. However, I think I can see some smaller white spots on the fins themselves, and that could be ich. The white stringy poop could be an internal issue.
I would suggest API General Cure plus Seachem Focus, but from the way you write, I suspect you're from the U.K., and I don't know what medications you have available.
I wonder - what if you try a FW diagnostic dip? It would at least help identify if one of the issues is flukes. Do you know how to do one? Perform a 5 minute FW dip in a dark container. Afterwards, search the bottom of the container for anything that could be dead worms. You may need a magnifying glass, a microscope is even better. If the fish shows some relief the next day, then flukes are indeed at least one of the issues and you can begin treatment.
Jay
I would suggest API General Cure plus Seachem Focus, but from the way you write, I suspect you're from the U.K., and I don't know what medications you have available.
I wonder - what if you try a FW diagnostic dip? It would at least help identify if one of the issues is flukes. Do you know how to do one? Perform a 5 minute FW dip in a dark container. Afterwards, search the bottom of the container for anything that could be dead worms. You may need a magnifying glass, a microscope is even better. If the fish shows some relief the next day, then flukes are indeed at least one of the issues and you can begin treatment.
Jay