I must preface this post by pointing out that I am not a doctor. If you have concerns about the health of your child, do not hesitate to take them to your GP.

My nine-month-old has been ill this week. Not seriously, but enough to give him a slight temperature and diarrhoea. He had two days of not being himself, during which I gave him baby paracetamol in order to lower his temperature. My main concern was the diarrhoea.

Diarrhoea in babies can be caused by many things: a viral infection, a bacterial infection, a food intolerance or allergy, and some people say that teething could even be a cause. One thing is clear, as long as your baby isn't running a high temperature, lethargic, vomiting or has blood in his poo, then diarrhoea itself isn't terribly serious. It must, however, be properly managed.

Dehydration is caused by either losing fluids through illness or exercise, for example, and not replacing those fluids. Dehydration can be much more than simply 'being a bit thirsty' and in babies and children can warrant a stay in hospital.

There are two types of dehydration:

Isotonic dehydration. This is when you lose both water and salts in the same proportions in which they are found in your cells. This can be caused by vomiting or diarrhoea.

Hypernatraemic dehydration. This is when one loses proportionately more water than salt and so there are high levels of salts in the blood. This most often happens in infants and children and can be caused by excessive vomiting or diarrhoea.

Mild dehydration is rarely a cause for concern as long as the underlying problem is being treated and fluid levels are kept up. Severe dehydration, however, can cause seizures, respiratory arrest or even life-threatening changes in heart functions. There is also a point at which severe dehydration cannot be treated at home and will require hospitalisation and being put on a drip. The risk of severe dehydration is greatest in babies and children.

If your baby is under the age of six months and is ill in any way, GO TO YOUR GP. Newborns are so delicate that the risk of treating even the seemingly most innocuous of illnesses on your own could cause serious problems.

If your little one is vomiting, more than the normal 'spitting up' in the first few months, or is projectile, accompanied by a high temperature and/or a rash or sleepiness and irritability, GO TO YOUR GP. No ifs, ands or buts. GO TO YOUR GP. Make sure that you keep your little one's fluids up by giving them small sips of boiled and cooled water along with the usual breastmilk or formula. Do not give fruit juices or carbonated drinks. Your GP may suggest you use a rehydration solution such as Dioralyte.

If your little one simply has a bit a diarrhoea – wet or loose stools – then it is possible for you to treat her at home with an altered diet.

It used to be that doctors recommended the BRAT diet – bananas, rice, apple sauce and toast – though these days they recommend allowing your little one to eat their normal foods even if they have diarrhea.

I found my son had lost his appetite for a day, so only wanted to eat a bit of banana, avocado and rice. As far as I was concerned, if he wanted to eat it, he could have it. I'm still breastfeeding him, so the first day of him being unwell, he was latched on most of the day and night. I had to make sure I didn't get dehydrated, too!

On the second day of his illness, I got some full fat, live, yoghurt which he loved. He ate tons of yoghurt and bananas on the second day – a bit of rice, a bit of avocado and I gave him sips of boiled and cooled water throughout the day. By the end of the day, he was considerably better.

By today, the third day, he is back to his normal old self. His appetite is back and he is happily causing trouble around the house. Though he no longer has the terrible diarrhea he had at first, his poos aren't 100% normal. I will keep giving him extra fluids for a few days, just to make sure.

For more information see NHS Direct's site on:
Diarrhoea
Diarrhoea and vomiting in children
Dehydration
Birth to five: childhood illness