I am worried about my 9 month old rabbit Pebbles, as over the last few weeks she has developed sticky poop.?

She has always had smelly poop, and her rear occasionally smells like strong onions, and b.o. but the poop has always been quite dry and large, so I was never worried. Her poop is now smaller, quite sticky and sometimes sticks to her bottom. She has been neutered. She is fed with a mixture of pellets and wheat based pet shop food, she absolutely adores veggies and has always had around 50grms of veggie mix a day, ie washed curly kale, green beans, spinach, and about half a carrot and plenty of hay, with no problems. I noticed the sticky poop started when I gave her some carrot stalks, but she has not had these for about 10 days now. Apart from sticky poops she seems absolutely fine, is a real character, and gets regular daily exercise, in fact she never sits still, and is not overweight. I have contacted the vet but they just say to cut down on her veggies, which I have done, but her poop still seems quite sticky and, as always, very very smelly. Can anyone he