[cypher]

How did you change her diet? If you just switched from one food to another that could have caused a problem, if you change mixes then it should always be done gradually mixes the old with the new, just adding a little of the new & increasing the amount of the new food over a week or more depending on how different the mix is.
Veg should be introduced gradually too, just a tiny piece once every few days then you can slowly build up to daily.
Diarrhoea is serious for hams & if she still has it then I would take her to the vet.