Are the droppings just soft stools, or are they cecal pellets? Fresh cecal pellets look like clusters of grapes or blackberries and often have a strong odor.
If it's soft droppings, then I would stop the green veggies.
If it's cecal pellets, then I would stop or cut way back on the pellets and maybe the veggies too.
Either way, I would try to get the rabbits to eat more hay. Hay is amazing at fixing intestinal issues.
Also... I would not recommend cabbage for rabbits. It really tends to make their tummies upset. That may be the whole problem right there.
And of course, carrots should be limited.
Do you have plantain weed growing in your yard? Try swapping the cabbage for that (unless, of course, you have pesticides on your lawn). Rabbits like it, and it's supposed to be very good for their digestive systems.
I know what they look like; I do not think that I have seen any recently.
I tend to limit the amount of hay that I give my rabbits, due to the fact that I am only occasionally able to get more for them.
I was not the one feeding them cabbage, but I have made sure that it will not happen anymore. I have not fed them any carrots in a long time.
I will try to feed them more weeds. Thank you for your time.