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Constipation and Diarrhea in Newborns


Many parents think their newborn baby is constipated if he is not passing bowel movements as frequently as they think he should. However, constipation is not defined by how frequently your baby passes stool. Rather, constipation is when the baby’s bowel movements are hard and cause pain or bleeding. The baby will groan or strain when trying to pass stool.

Other common symptoms of constipation are as follows:

  • stool streaked with blood, if there are cracks in the baby’s anus caused by the passing of hard stool

  • abdominal pain

  • irritability

Newborn babies who are breastfed exclusively are very rarely constipated. Constipation is more common in bottle fed babies.

If your newborn baby is having difficulty passing a bowel movement, try moving his legs in a bicycle fashion. Sometimes other treatments are needed to help your baby have a bowel movement, such as water or diluted prune juice. These treatments should first be discussed with your doctor.

Infrequent bowel movements in newborn babies

Usually in the first couple of days of life, a newborn baby will pass a dark green or black, tarry substance called meconium. Around the third day or so, the newborn baby’s bowel movements should become more frequent, especially if the newborn baby is breastfeeding. The stool itself changes to a lighter brown, tan, or yellow colour and it is relatively soft or curd like in consistency. Breastfeeding newborn babies may pass three to four bowel movements per day within the first two weeks. The bowel movements of bottle fed babies may be a bit less frequent. The colour and consistency of your baby’s bowel movements will change over time as new foods are introduced in the later part of the first year.  

If your newborn baby is having infrequent bowel movements during this time, it could be a sign that your baby isn't getting enough to eat. If your newborn baby is not having frequent bowel movements, be sure to discuss with your doctor your baby's feeding schedule, amount of wet diapers, and if he seems to be gaining weight.


Diarrhea is when the newborn baby passes very runny, liquidy stools, sometimes at an increased frequency or more volume than normal. There may be mucus in the stool. Diarrhea is sometimes associated with vomiting.

Diarrhea is often caused by a bacterial or viral infection. The infection is transmitted to the newborn baby through contaminated foods or if there is contact with contaminated stool. Diarrhea may be due to another type of illness. Less frequently, it may be due to sensitivity to something in the baby’s diet or feeding intolerance. Diarrhea may also be a side effect of antibiotic medication in some babies.

When to see the doctor

Diarrhea can be very serious in newborn babies. If you notice any change in your newborn baby’s bowel movements, make sure to mention it to your doctor. If your baby has diarrhea and vomiting, it is most likely a sign of infection. If your baby shows any signs of dehydration, such as dry mouth, less than six wet diapers per day, sunken eyes, a sunken fontanelle, or dry skin, it could potentially be very dangerous.

Bring your newborn baby to the doctor as soon as possible if he has loose, watery stools for 24 hours, or if diarrhea is accompanied by any of the following symptoms:

  • dehydration

  • vomiting

  • fever

  • blood in stool

Treatment of diarrhea

The treatment of diarrhea depends on its cause. Sometimes a dietary change is made, and sometimes medication is required. Do not give your newborn baby any medication unless it is prescribed by a doctor.

Here are a few tips that your doctor may recommend:

  • If your newborn baby is breastfeeding, continue to feed him as normal.

  • If your baby is vomiting, you may need to feed him in smaller amounts but more frequently. If you are breastfeeding, this means keeping your baby at the breast for a shorter amount of time at each feeding.

  • To protect against dehydration, you might need to give your baby an electrolyte solution such as Pedialyte in between feedings. Alternately, you may need to replace the feedings entirely with the electrolyte solution.

  • If you are bottle feeding and your baby’s diarrhea continues for more than two weeks, you may need to make a change in formula. You should discuss this with your baby’s doctor.

Diarrhea and vomiting are sometimes signs of infection. In newborn babies and young infants, infections can become serious very quickly, and dehydration from diarrhea and vomiting can develop quickly. It is important to have your baby treated as soon as possible if an infection is suspected. Special diagnostic tests may be required, and your baby may need to be treated in the hospital with intravenous fluids.

A note about diaper rash

Diarrhea can cause irritation on your newborn baby’s bottom, which can lead to diaper rash.

If your newborn baby develops a diaper rash, change him frequently, especially after each bowel movement. Stop using baby wipes, as they can be irritating, since many commercially prepared wipes contain alcohol. Instead, wipe your baby’s bottom with a wet cloth. Try to give your baby as much “bare bum time” as possible, to allow it to air out. Spread a thick layer of diaper cream on your baby’s bottom before putting on the next diaper. Avoid the urge to put powder on his bottom, as baby powders tend to be ineffective and may cause breathing problems for your baby.

If your newborn baby develops a yeast infection, which is a stubborn rash on the genitals that can extend up to the abdomen and down the thighs, seek medical attention as soon as you can. There is a special cream that can be used to treat this condition effectively.

Hazel Pleasants, RN, MN

Andrew James, MBChB, FRACP, FRCPC