Baby Boy Is Peeing Up Out of His Diaper (Or Through It Completely!)

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You just finished changing your baby boy’s diaper, and you’ve settled down together for some giggles and play. A short time later, you notice that he is suddenly soaking wet again and has pee leaking over his diaper, or has soaked through the diaper completely. You scoop him up to change him again. Not for the first time, you wonder – why is your baby boy peeing through his diaper?

Urine leaks from a baby’s diaper may occur when the diaper doesn’t fit properly. A diaper that is too large may prevent the urine from being absorbed before it leaks out, and a diaper that is too small may not be absorbent enough. Baby boys may experience leaks around their belly button because their penis is pointed up instead of toward the diaper.

Read on for information on the reasons why your baby boy is peeing out of his diaper and some tips and suggestions to fix the problem and keep your baby dry.

My baby boy is peeing up out of the top of his diaper

It’s happened again. Your little guy has peed up out of his diaper again. You toss another urine-soaked onesie onto the top of your overflowing laundry pile, frustrated and concerned. Lately, it feels as though there is no diaper waistband in the world that is a match for your baby boy’s pee stream.

Fortunately, urine leaks that seep over the top of a baby boy’s diaper are a common, preventable problem with some easy fixes.

Why it is happening

One likely cause of this type of diaper leak is your little guy’s anatomy.

If your baby boy’s penis is pointing upwards in their diaper, their urine stream will then also point upward, wetting the waistband of their diaper and whatever lies beyond. This can often happen when your baby is laying and playing on their tummy and their penis is positioned upward.

Another possible reason for your baby’s top-of-the-diaper pee leaks is that they are wearing a diaper that is too big for them. If a diaper fits too loosely around your baby’s waist, his urine may travel right up and out of the roomy diaper waistband rather than absorb into his diaper.


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If you have checked that your baby is wearing a diaper that is the right size and you know that their penis is not pointing upward when leaks from the top of the diaper are occurring, you might be diapering your baby too low across their belly.

How to fix it

When changing your baby’s diaper, pull the front of the diaper up just a little bit higher than where the back part sits before you tape your baby’s diaper into place.

Make sure that the diaper is pulled high enough in the front that it covers their belly button. More diaper coverage on your baby’s belly means more absorbent material is ready and in place for any potential urine stream or leak that might flow up the front. 

Another easy solution is to use your thumb to position your baby’s penis so that it is pointing down, toward the most absorbent part of his diaper, while you are changing him. Hold your finger there until you have taped both sides of his diaper.

What to do if your baby boy is peeing out the back of his diaper

A baby with a pee-soaked back and mattress cover is an unhappy baby indeed. And the parent of a baby who is experiencing leaks from the back of his diaper is not only unhappy but exhausted and frustrated as well.

But you can rest easy, leaks from the back of your baby’s diaper are common and preventable.

Why it is happening

The most likely cause of repeated incidences of urine leakage from the back of your baby’s diaper is that they are wearing a diaper that is too large and fits too loosely on your baby’s back to absorb his urine adequately. 

Back leaks that happen infrequently can be the result of poor diaper placement. When you change your baby boy, who may be busy wiggling away and don’t create a good seal across your baby’s back with the diaper’s waistband, this can provide your baby’s pee the opportunity to escape toward his back.

It’s also possible that your baby’s movements have shifted the positioning of their diaper, leaving ample openings or less coverage in the back of his diaper.

How to fix it

This type of leak requires a diaper fit check.

Your baby’s diaper should sit somewhat snuggly over his back, with no large gaps or openings. If you check your baby’s diaper and the material forms a large gap between your baby’s back and their diaper, your baby needs a diaper in a smaller size.

When you change your baby, make sure that you are pulling the sides of their diaper snuggly enough over your baby’s belly that you create a smooth seal out of the waistband of their diaper in the back.

What if baby boy keeps peeing through his diaper?

You think your baby is dry and tidy in his diaper and you’re really getting a hang of this parenting thing. Then you catch a glance at your little guy, who is waddling across the room, his pants hanging heavy and sagging. One look tells you they are clearly soaked with pee again.

Why does he keep peeing straight through his diaper and what can you do about it?

Why it is happening

It’s very possible that your baby boy needs a larger diaper that is more absorbent.

As your baby boy grows and develops, he will begin to produce a greater quantity of urine throughout the day which must be absorbed by a diaper to prevent leaks. For nighttime leaks, babies usually require special overnight diapers which absorb more urine and keep them dry for longer lengths of time.

A baby boy also requires frequent diaper changes. Urine will leak straight through their diaper if they are not changed frequently enough.

How to fix it

When your baby is experiencing pee leaks through their diaper is to check to make sure your baby is wearing a diaper that is the correct size and a good fit.

Signs your baby’s diaper fits properly:

  • The waistband fits snuggly.
  • The waistband sits just below baby’s belly button.
  • There are no gaps in coverage around your baby’s thighs or belly.
  • Your baby’s bottom is completely covered.
  • You have room for two fingers between baby’s waist and the waistband.
  • There are no red marks around legs or stomach after wearing.
  • Your baby’s weight is within the weight range listed on the packaging.

Your baby’s diaper is too small if you see red marks from their diaper on their belly or legs, you don’t have room to run two fingers around your baby’s waist under the waistband of their diaper, or you cannot pull it to cover their belly up to their belly button and cover their bottom completely, or they are leaking through their diapers even though you are changing them every 2-3 hours.

Your baby’s diaper is too big if there is excessive gaping between the diaper and your baby’s belly and legs, you can fit more than two fingers under the waistband of your baby’s diaper, there is excess diaper material over their belly and bottom, they are experiencing regular poopy diaper blowouts, or urine is streaming directly out of their diaper.

We hope that we’ve given you some quality tips and information to help you keep your baby nice and dry! As always, if you have concerns that your baby boy may have a medical problem, please consult your baby’s pediatrician.

Joshua Bartlett
Joshua Bartlett

My name is Joshua Bartlett I run this blog with my wife Jarah. We have more than 11 years of parenting experience including three girls and one boy. I started this blog in late 2018 when I realized that I was dealing with baby-related issues on a constant basis…please read more about me here!

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