Drink milk every 36 hours. This not only prevents/soothes hunger, but calcium binds to fat so that it can't be absorbed. This also helps to fend off the supposed "Starvation Mode" so that you don't gain more from eating less. Besides this, it's really healthy and good for brittle bones and hair.
Don't use laxatives. Anything you think you lost is being absorbed. The only "weight" you lost is the excrement that was moving through you anyway. You're not thinner and you're not going to lose any fat that way. If you really insist, eat celery. It's high in fiber and is a much healthier way.
If it's been three days, keep going! At three days, your body will start to try to conserve food, making you gain more if you binge after then! I would go at least 5-7 days total.