The age that babies wear size 6 diapers is usually by age 3 years old and by 2 years old babies typically wear a size 4 or size 5 diaper.
My son who is now 8 wore a size 4 diaper when he was 2 and wore a size 6 diaper when he was 3 and now at 8 he can still wear a size 6 diaper but since he's a heavy wetter at night we up to size 7 diapers which Gentle Steps size 7 diapers which are very absorbent.
All kids are different and built different and some diaper brands run larger than others.
Most kids will be potty trained before they need a size 6 diaper.
A common reason your baby is peeing out the back of his diaper is the diaper is either too small or not fitted properly.
When the baby is leaking pee out of the back of his diaper it's usually because the diaper is too small and it's time to go up a size in diapers and if the diaper is leaking out the legs the diaper leg cuffs could need pulling outwards and are tucked in and should be untucked.
A too large diaper could also cause leaks around the legs and a too small diaper could cause leaks of pee around the legs and back.
You can know if a diaper is too small by placing 2 fingers under the waistband of the diaper when fastened.
If you cannot fit 2 fingers under the diapers waistband when fastened then the diaper is too small and it's time for a bigger size diaper.
Another sign that the diaper is too small is the diaper is leaving red marks on your baby's waist and legs or the baby is having constant leaks such as pee or poop coming out the diaper.
If poop is leaking out the back of the diaper or pee is leaking from the leg gathers the diaper could be too small and you should go up a size in diapers.
A common reason why your baby's poop is leaking out of the back of the diaper is because the diaper is either too small or the diaper is not fitting properly.
If your baby keeps having poop leaking out the back of their diaper it's usually a good idea and sign that it's time to go up a size in diapers.
When poop is leaking out the legs, you should make sure that the diaper leg cuffs and leak guards are pulled out and snuggly fit around your baby's legs.
Even when the diaper is fitting normally it is normal for the baby to have poop explosions and poop leaks out the back of the diaper.
When placing the diaper under baby's bottom, make sure you pull the diaper high enough to prevent leakage.
Raise the back portion slightly higher than the front portion and then fasten the tape diagonally downwards.
Sometimes placing a paper towel or a few baby wipes down the back of the diaper and sticking out slightly above the diaper in the back can help with the poop leaks out of the back of the diaper.
Blowouts of baby poop tend to happen at the back of the diaper where it is hard to create a seal.
In many cases baby diaper poop blowouts happen because of the wrong size diaper or diapers that aren't fully snug on the baby.
Sometimes a baby will need a slightly bigger diaper for absorbency and proper fit even if they are in the correct weight range of the diaper.
If you can't comfortably fit two fingers under the waistband of the fastened diaper, it's time for a bigger size diaper.
You may need to go up a size in diapers if you notice red marks on your baby's belly or thighs when you remove the diaper.
If the baby's diaper isn't fully covering your baby's bottom, choose a bigger size.
And if your baby is wearing the wrong size diaper, you are in for more diaper poop blowouts.
And also if the baby's diaper is too small, the diaper won't be able to contain your baby's poop and lead to poop blowouts.
And on the other hand if the baby's diaper is too large, it may cause gaps and lead to leaks, especially around the diaper leg cuffs.