Cardiomegaly...What's next?

My cat has been having bowel issues since Friday.  Since Saturday, his appetite has decreased.  He's my first pet and I freaked, so I took him to an emergency clinic last night.  They did xrays and couldn't see anything wrong except for a lot of gas in the colon.  Unfortunately, the vet noticed a spot close to the heart that looked like either fat or a tumor.  The radiologist had already gone home for the day, so we had to wait until this afternoon when they faxed it to my regular vet's office.  My regular vet is a discount type place and runs mainly off of volunteers, to the point where they don't even have someone available to answer the phones.  So when I showed up for the report, they just gave it to me and sent me on my way.  When I got home and read it, I was equally confused and devastated.  These are some snippets from the report.

"Conclusion:  1. Cardiomegaly, differentials include cardiomyopathy and congenital cardiac disease. 2. Widening of the cranial mediastinum on the ventrodorsal projection and soft tissue opacity superimposed dorsal to the sternum, have differentials to include branchial cyst, other mediastinal mass, and lymphadenopathy. 3. Bilaterally small kidneys. 4. Radiographic evidence of constipation is not identified"

I have an appointment in the afternoon tomorrow with a new vet to help interpret these results, but I know that it's not looking good.  I'm pretty devastated and don't understand how he could have this.  Before the bowel issues, he seemed like a perfectly happy and healthy 2 year old cat.  To top it off, he still hasn't had a bowel movement since Friday, and he's still not eating or drinking much.  Otherwise he's acting pretty normal, but I'm still worrying like crazy.  I hope that they can figure out what's wrong tomorrow and give me hope that he has a future even with the cardiomegaly..

I hope they can figure it out too. I don't know much about heart issues in cats. Many vibes for your cat.

Did the vet mention if the bowel issues are related? It seems weird that heart issues would show up as bowel issues. Of course if he's not eating or drinking much that could be the issue with the lack of bowel movement. Are there other bowel issues on top of the lack of poop?

Not eating and drinking could lead to another set of problems, mainly fatty liver disease and dehydration. If he is to get better, he must continue to eat and drink. If he is not doing that on his own, and it's already been several days, he may need supportive care. Something definitely to discuss with your vets.

We managed to get him to the vet yesterday.  They did blood work and urinalysis...all good!  Mitch is eating and drinking almost back to normal again, and he's had one BM since yesterday and has urinated at least once.  The ONLY thing that's still slightly concerning is that he keeps hiding under the bed.  Prior to the start of the bowel issue, he would only do this if we ran the vacuum cleaner.  Is it possible that now he just kinds it as a place of comfort and likes being there, or could he STILL be in pain even though he's not acting like it and is pretty much back to normal?

As far as the enlarged heart, the vet seemed to think that it won't be an issue unless the heart walls are thickened.  The only well to tell, and only way to figure out what the 1.5cm mass near the heart is, would be to get an ultrasound.  They had to refer me elsewhere to get that, and the earliest I can get in is September 15th.  So hopefully then, we'll have all the answers we need.