Are bladder infections common in toddler girls? What can cause them? Does a "cold in your bladder" exist (i.e. a bladder infection as a result of a virus)? Are yeast infections in this age group a possibility, and what are the symptoms?
Urinary tract infections—often referred to simply as "UTIs"—are common in childhood. They are most common in boys under 1 year and girls younger than 4. To give you a sense of just how common, it has been estimated that overall, nearly one out of 10 infants (7 percent) who have a fever have an underlying UTI. In children under 2, they are most often associated with symptoms such as a high fever and/or tenderness of the lower belly (i.e. over the bladder), and are more likely to be found in kids who have had a prior UTI.
As for what causes UTIs in children, a vast majority (on the order of 85 percent) are caused by Escherichia coli—a very common type of bacteria that is usually easy to treat with the appropriate antibiotic. While it is possible for viruses and other organisms (including yeast and fungi) to cause UTIs, these are much less common causes. While it's therefore possible that the phrase "a cold in your bladder," you asked about could refer specifically to a viral UTI, it would be far less likely. Similarly, a true yeast infection of the bladder and/or urinary tract is possible but unlikely in an otherwise healthy individual.
A Candida yeast infection of the skin, however, is much more common and can cause symptoms that might easily be confused for a urinary tract infection. These include a stinging feeling when urinating (often referred to as "dysuria") and/or irritation of the genital/diaper area, as well as the classic yeast-infection diaper rash.
Given that it's important to diagnose both UTIs and yeast infections sooner rather than later and to get them treated appropriately, you should never hesitate to raise any concerns with your child's pediatrician.