Goldfish not eating

Question
Hi,
my goldfish was quite ill about four weeks ago with what turned out to be anchor worms. I treated him for them and the treatment appeared to work as the worms disappeared. He has not been eating properly for a few weeks though and I haven't seen him eat for a week or more. I feed him flakes, so he would normally come up to the surface to eat but he hasn't been doing this recently. He also used to search for flakes in the stones at the bottom of the tank but has stopped doing this. He stays still at the bottom of the tank for long periods of time and then won't settle the rest of the time. He now seems to have a bit of trouble swimming as he seems to tilt to one side or the other occasionally and seems unable to tilt upwards or downwards to feed. I have also noticed that he now has white/clear long faeces as well and I can't find this as a symptom on any of the websites that I checked which is why I decided to ask my question. He was constipated a while ago so I fed him peas and these worked that time but he doesn't seem to be eating at all now so he won't eat any peas that I give him. (I say him but I don't actually know whether he is male or female. I don't know if that's important.)  Do you know what could be wrong with him?

Thank you,
Ciara

Answer
Clara, it sounds like the fish could have an internal infection of some sort. Purchase a broad spectrum antibiotic such as Maracyn, this is what I always use for my fish sicknesses and it has always worked. The Nitrite levels in the tank could be at a lethal level as well. You need to monitor the water parameters in the tank to be certain that the water quality remains safe and healthy for your fish. I do believe this may be an issue. Purchase some sort of testing supplies from a pet store. If your able to, get quick dip which is a test strip that tests for 4 different things in your water. Good luck and if you have any other questions, feel free to let me know.