Candida die-off and candidiasis symptoms can produce the same illness issues.
How long one goes through die-off depends on how much excess candida is built up in the gut. I was on a candida diet, a very strict one too, for 8 months, and still one little slip-up in experimenting (I learned what worked and what didn't the hard way) and massive symptoms again occurred. It was only at about the end of 8 months that I started using Diflucan that finally got some real relief. My kidneys ached like mad for about a week (die-off). I thought I was getting a urinary tract infection. (I wasn't) Sometime after a week the die-off symptoms began to slow down. It took me 2 years before I could eat raw veggies and drink any amount of milk or milk products again.
Systemic candida is rare, but the waste product of the candida can circulate throughout the system, causing pretty much any kind of health issue known to science.