Vegetable question!?

Hiya, I have two bunnies who are four months old. They are brother and sister and both are getting neutered within the next few days. I was just wondering how to go about introducing them to veges. They have very sensitive tummies but both eat grass, hay, pellets and drink water as normal. Which verges would you introduce and how ?

Ps the reason they're not on verges yet is because they've just changed hands had their former owner couldn't really care for them as well as she would have liked

Thanks in advance

It would be best to give them a week or so to recover from their neuter before introducing anything new - the neuter will be stressful so best not to add another trigger for problems.

I would go for forage like dandelion and bramble as they are already eating grass, you could also dry some fresh herbs.

What dry food/how much as they are at the moment? Cutting back on that may help with tummy issues.