Welcome to Gaia! ::

I left on vacation for about two weeks.
I have 2 aquariums; A goldfish tank of 30 gallons with 3 goldfish in it.
And a tropical 20 gallon tank with 2 blood gouramis and 5 cardinal tetras.
When I left both tanks had been in perfect shape, they had just been cleaned.

When I came back I found out the maid had been feeding the fish, both tanks with handfulls of goldfish food.
The gold fish were a bit bloated, but for the rest fine.

At the tropical tank the filter had died, all the plants had died and started to rot, and residue of goldfish granuals drifted on the surface.
It was a revoltingly smelly situaltion.

The only fish alive were one cardinal and one blood gourami.
I imidiately placed them in the goldfish tank (which has the same temperature about, 25 celcius) hoping they would survive.
Initially I feared most for the tetra since it was so pale and sluggish and I've known labyrinth fish to be a bit less vulnerable then cardinals.

The tetra recovered remarcably and is quite at ease in the goldfish tank.

The gourami is still bloated however and he seems to swelling. I have not yet seen him poop like the other fish do so much now.
I fear he may have opstipation or a prasite (worm?) in him.
I placed him in a 5 liter tank just in case it's something contagious.
But I'd really rather not have him die.

So how can I find out what's wrong?
If it's constipation how can I cure it, if it's a worm what can I do?
None of these fish have ever been sick, apart from the goldfish who had ick when I got them a year ago.

Edit: I cleaned the tank today and found a bit of pale white poop. At least it poops but not in the amount I'm used to seeing come out of a fish, and I don't think white is a that healty color.....

Seriously?
Thank you so much!
I doubt the petshop has a de wormer. We don't have any profesional fish orientated petshops where I live mad
I had to place a special order to buy ick medicine...