According to Ayurveda, it is important to evacuate the bowels every morning. If during the day, you carry around the waste material you created at night, you may absorb some of that waste material into your system which may weaken your immune system.
Sit or better squat on the toilet, and have a bowel movement. Even if you don’t the urge, sit for a few minutes, without forcing. If you do that every day, following your glass of hot or warm water, the habit should develop.