FamilyDoctor.org says that most children show signs that they are ready to be potty trained between 18 to 24 months. Some of these signs include a child being able to communicate when her diaper is dirty, being interested in the toilet and being able to physically pull pants up and down. It is a parent's personal preference whether to use a regular-sized toilet or a potty chair when potty training, but there are some things to consider when making the choice.
Ease of Use
As detailed on Babycenter.com, an adapter seat is a special seat that attaches to the toilet. It may reduce some anxiety for a toddler if he fears falling in the toilet. The adapter seat may be easier to use because it can be taken from room to room, place to place. Although a potty chair can be transported as well, it is more bulky and more clean up is involved.
Safety
Because a potty chair is low to the ground and is a child's size, as described on Babycenter.com, there is not much risk for falling off or even into the potty. This can make potty training easier because the child has a higher comfort level than he would with a toilet.
Cleanliness
There is more cleanup involved with a potty chair than a regular toilet. If a chair is not cleaned properly or regularly, it can harvest harmful bacteria. A potty chair must be emptied every time, while a toilet can simply be flushed. As described at iVillage.com, toddlers can develop a fascination with feces and try to play with it. Although this can happen in a regular toilet as well, it is more accessible in a potty chair.
Convenience
A toilet can be more convenient than a potty chair because one can be found virtually anywhere. It is easier to carry an adapter seat around than a potty chair.
A potty chair has its conveniences as well. More than one person can use the restroom at a time. FamilyDoctor.org says that when first introducing a child to potty training, a potty chair can be placed in a play area where she can sit on it and become familiar with it. A real toilet does not offer that option.
Extra Equipment
If a parent does not wish to purchase any additional equipment (a potty chair) for a bathroom, a regular toilet is an ideal choice for potty training. However, as Parenting.com suggests, a foot stool (in order for the child to climb onto the toilet) and a toilet adapter may be necessary.


