Water is the best medicine

One man was so bad and decided to go to the doctor: After examinating the man the doctor said: I am going to prescribe some pills for you:
In the morning, take this red pill with a glass of water.
At midday take this blue pill with a glass of water.
At night before dinner take this green pill  with a glass of water.
Before going to the bed take this yellow pill with glass of water;
The man was amazing and asked: Doctor, am I so bad to take so much pill?
No, answered the doctor: YOU NEED DRINK