sick poult, need advice

[valewife]

Two days ago, one of my 6 week old poults became droopy, fluffed, stopped eating, and had yellow colored runny droppings. My vets ran a fecal and it's clean. I'm giving him Oxytetracycline and electrolytes in sugar water now. He's drinking well but not eating. His droppings are occasionally slightly yellow now, but mostly they are like egg whites. No signs of respiratory problems.
I had treated my 3 poults with a course of Sulmet last week because another bird began with the same symptoms except the droppings were very dark, runny and smelly. Within two days he was back to normal and appears very healthy now.
My vets are wonderful but don't treat poultry. No diagnosis yet but have suggested metronidazole.
The 3 poults are housed in a clean coop and run and are out in the yard and garden with me some every day. I also have chickens that free range.
Any ideas ? Could the Sulmet have anything to do with this second bird's symptoms ?
Thanks for any help.

 

[chickenzoo]

So he was treated with Sulmet before? for how many days? metronidazole would be my next step also if it doesn't seem to be coccidia. I use Fish Zole, a fish medication that has that as it's ingredient.

 

[valewife]

5 day course on the Sulmet, as directed on the bottle.
And I had a fecal done after the third day on Sulmet and it came back clean but I completed the tx.

 

[valewife]

Oops- 6 days on Sulmet. 2 days at full dose then 4 days at half dose.