Dr Phil Kieran: Tummy bug has left my child with low energy levels

Dr Phil Kieran: "Tummy bugs usually last five to seven days and then settle down. One of the most common causes of severe gastroenteritis used to be rotavirus, which sometimes resulted in young children going to hospital due to dehydration. This is no longer the case since the introduction of the rotavirus vaccine, now included in the infant vaccine schedule"

My five-year-old daughter picked up a tummy bug about three weeks ago. While she got over the symptoms within a few days, her energy levels are still low.

Tummy bugs or gastroenteritis (gastro) are one of the most common illnesses kids get. Almost all of us will have had gastro during our lives and many of us will get bouts of it again when we become parents (by catching everything our kids get). The vast majority of tummy upsets are caused by viruses and the most common is a little bug known as norovirus or the 'winter vomiting bug'. There are also some important bacterial and parasitic causes of tummy bugs and we will test for these in children who are particularly unwell or in high-risk categories (like where a local well has been contaminated or in areas where unpasteurised milk is usually ingested).

Tummy bugs usually last five to seven days and then settle down. One of the most common causes of severe gastroenteritis used to be rotavirus, which sometimes resulted in young children going to hospital due to dehydration. This is no longer the case since the introduction of the rotavirus vaccine, now included in the infant vaccine schedule.

The body usually clears the infection itself pretty quickly, and we typically don’t recommend using medication to reduce diarrhoea. 

Your child will frequently not feel like eating and keeping them hydrated is essential. You could try giving small children a sip of water every five minutes for an hour or two, which can help them feel well enough to drink bigger volumes. If you are concerned that your child is dehydrated, bring them to the doctor.

Dr Phil Kieran: "Up to 10% of children with gastroenteritis will develop mild lactose intolerance following the illness, which can cause diarrhoea, bloating, and fatigue. This is caused by temporary damage to the gut lining and usually settles after one to three weeks."

In your daughter's case, the gastro has settled, but she is not back to her energetic self.  Post-viral fatigue is very common and usually starts to resolve around week three, so if she starts to pick up, you likely have nothing to worry about. 

However, there are a few things to bear in mind regarding gastroenteritis. Up to 10% of children with gastroenteritis will develop mild lactose intolerance following the illness, which can cause diarrhoea, bloating, and fatigue. This is caused by temporary damage to the gut lining and usually settles after one to three weeks.

I would recommend stopping lactose and seeing if her energy levels improve. If they do, you should re-introduce lactose after about two weeks, as I am not keen on removing any food groups long-term from children’s diets.

If this doesn’t help and your daughter is back to a normal diet and normal bowel movements, it may be a good idea to bring her to her GP for an overall check-up to make sure there isn’t any other reason for her low energy.

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