Thank you for the additional information, though it has raised a few more questions.
What urinary based history has he had previously?
When were this urine test performed?
Is he on any medications currently?
I would first advise because he does have a possible urinary based history, that is key that we know that he is urinating. If he isn't urinating and has a urinary blockage, this is an emergency situation for him. Some cats with unrecognized blockages, can become subdued (anorexic, nauseous, lethargic, and can vomit) when urinary toxins begin to build up in the blood. Therefore, if there is any chance that this is the case, then he needs to see a vet now.
Otherwise, from the feeding behavior you are describing, this is very typical of cats who want to eat but have something that gives them reason to hold back. In a way, it is quite a wise strategy in the cat, as they avoid the action that will cause a negative effect that they want to avoid. But on the other hand, their logic does back fire, as cats were not designed to be off their food long term (and can suffer even worse effects due to anorexia then they'd have had with the original condition). The most common reasons a cat will act like they want food then leave it untouched is oral pain and nausea (either with or without vomiting).
Oral pain can arise in cats for a variety of reasons. Often dental disease is to blame but it can be sudden things like foreign bodies lodged in the teeth (or strings can get trapped under the tongue) or injuries to the mouth or tongue. The most straight forward way to rule this out is an examination of the mouth. It might be possible (if he will allow you a look safely) that you will be able to identify if there is something abnormal going on in the mouth, but often cats with oral pain or discomfort will not be amenable to anyone having a look (so if this is likely it will probably be best for a vet to check).
The other reason, and what I would suspect to be more likely in Edsel's case would be nausea (as he is a young, indoor cat...but then he have a history of mischief making that I don't know about). Nausea can be a precursor to a vomiting bug or it can be the extent of the signs. If he has picked up a bug (viral or bacterial), he subdued behavior might be due to fever.
I would advise tempting your cat to eat by either giving him something he really fancies (that is cat safe, of course) or you can try giving him a small volume of a light/easily digestible diet. Examples of this would be boiled chicken, scrambled eggs (made with water and not milk), or there are also veterinary prescription diets that can be used in cases of gastroenteritis, notable Hill’s I/D or Royal Canin’s sensitivity. These tend to be light on the stomach and not put much stress on the troubled digestive system.I would offer a small amount and if he is does eat it and keeps that down, a bit more can be offered.
If you are concerned that he is becoming dehydrated, you can try an encourage him to drink but offering fresh water or even low-sodium chicken broth. If he isn’t amenable to these, you can syringe feed him pedialyte. A typical maintenance rate for hydration in an animal is 2 millilitres for every kilogram of weight per hour. (2ml/kg x kg x 24hr). This value will give you the total he needs for the day and is a good starting point to give you an idea of his daily requirement. If he vomit when you given pedialyte, I would discontinue this as a therapy. (since we don’t want him vomiting more because of our intervention).
As nausea is possible in his case and cats can go off their food if they are nauseous (even without vomiting),there are also a number of antacids that are available over the counter and pet friendly. I would advise only treating with one, and administering a half hour before offering food. Two I tend to recommend are
Pepcid (http://www.petplace.com/drug-library/famotidine-pepcid/page1.aspx) or
Zantac (http://www.petplace.com/drug-library/ranitidine-hcl-zantac/page1.aspx) .
As long as he is urinating normally, you may intitiate these treatments, but if he isn't perking up or you do not see improvement over the next 24 hours, then I would advise taking him to the vet so that they can rule out possible causes for his being off color. Sometimes we find that cats with tummy bugs or festering infections that won’t settle without veterinary intervention. The vet will be able to give antibiotics and anti-vomiting medications by injection, to get him back on tract as quick as possible.
If you do need a vet and your own is closed, then you can find an emergency vet here, http://www.veccs.org/index.php?option=com_hospitals&nationid=1&Itemid=193
I hope this information is helpful.
Please let me know if you have any further questions.
If you have no further questions, I would be grateful if you would press the wee green accept.