Same reason as women - bacteria in the urethra.
Bladder infections that cause blood in the urine are relatively common, affecting about 3-8 of women and 1-2 of men each year.
You can find symptoms of Urinary Tract, and Bladder Infections at http://www.webmd.com/a-to-z-guides/understanding-bladder-infections-symptoms
Usually, bladder infections symptoms include having to go a lot, but when you try, not much comes out. Bladder infections sometimes has stomach pain, tiredness, and pain when going to the bathroom.
I am not sure Gatorade can be a cause of bladder infections but in my experience it has been a contributing factor to bladder irritation.
No
The most common cause of bladder infections is bacteria entering the urinary tract through the urethra.
urinary track infections
Yes
It's filtered out by the kidneys and goes through the ureters down to the bladder.
Yes, bladder infections can sometimes cause bleeding in the urine. This is known as hematuria and can be a symptom of a bladder infection. It is important to seek medical attention if you experience this symptom.
Microorganisms cause infections which affect the urinary system. Usally the infections start in the bladder and spread to the kidneys.
It is important to consult a healthcare professional if you experience symptoms of bladder infections, such as blood in urine.