If dialysis is given once then one has to take it always?or by living on only veggies one can stop it?

Dialysis: There are people who are on dialysis only temporarily (they've had temporary kidney failure due to medications or infection), but some are on for the rest of their lives. It depends on the underlying kidney disease and if its reversible. And while veggies are good for you, they won't reverse permanent kidney failure.

Depends on disease: If a person was normal and then got a new illness (an acute illness) causing acute kidney failure, he might need dialysis while waiting for his kidneys to heal. If his kidneys heal well enough, he can stop dialysis. However, if a person has chronic kidney disease and has been losing kidney function over the years, his kidneys don't heal up after he starts dialysis. He continues to need dialysis.