helo mate , ive had this , its adeno coli ! clear wet droppings with a black worm type fecis in the middle , firstly if you havent vaccinated for paramyxo do it now , if this illness is not treated it does lead to nervouse problems in the bird , firstly do not feed them any maize or small seed , and treat them with a 4-1 , 7 days ! then at end of treatment give vito pro combo 2 days then 2 days milton 1 teaspoon to 4 ltrs water , this will clear it up and should stop it spreading ! but keep an eye on any birds that begin stairing in to space as this is signs of paramyxo ! they can get over this but can be carriers hope this helps mate it did mine !! you should spray everything in loft with virkon s !!!