Diarrhea in children

Gastroenteritis describes an infection in the gut primarily due to viruses like rotavirus, adenovirus, and norovirus, which spread between children from infected stool to fingers to mouth, or from infected food. They will usually eat very little for a few days. They will often say their tummy hurts, pain may come in waves or cramps, they may have a temperature, and they may have some vomiting or feeling sick.

Bacterial gastroenteritis is less common and often comes from food, contaminated water, or poor hygiene, and it is more often associated with travel abroad to certain countries. The diarrhea is sometimes bloody, and your child might be pretty unwell with a fever. Infection with parasites is also possible to bring home from certain parts of the world.

Prolonged or repeated courses of antibiotics can change the gut’s natural protective bacteria – the microbiome – and allow certain bacteria to overtake and cause gut disruption and diarrhea. And those children on medication or with conditions that suppress the immune system are particularly vulnerable to gastroenteritis.

Children may have food intolerances or allergies that cause diarrhea, such as gluten or lactose intolerance. This may also come with stomach cramps, bloating, and - in babies - poor feeding or failure to gain weight.

Occasionally children may present with colitis, an inflammation of the gut that sometimes indicates a long-term condition like inflammatory bowel disease. In this case, mucus and blood might be mixed with the stool, they may feel quite tired, and they may be losing weight.

With infective gastroenteritis, your child or baby is contagious from the time they get the first symptoms of diarrhea until they have recovered. They should stay off school and avoid pregnant or immunocompromised people until their symptoms have resolved for 48 hours.

If you have more than one bathroom, try to keep one just for them to use, and avoid sharing cutlery or cups, clothes or towels with anyone else in your household. Everyone in the house should follow strict hand hygiene, including washing hands with soap and water after toileting and preparing or eating food.

The main thing to do is to keep the child or baby hydrated.

Babies should continue to feed as usual, and you can supplement with a little water between feeds. Older children should be encouraged to have regular, small, but frequent sips of water to prevent dehydration. Keep a monitor of this and how much they’re passing urine.

Diarrhea can cause salts and minerals to be lost from the body alongside water, especially potassium. This can make them feel even worse and be dangerous with large losses. Oral rehydration treatments can help replace lost salts and keep their bodies balanced.

Don’t force food unless they’re interested, and start with bland foods like dry toast or watered-down soups.

Avoid dairy, spicy foods, sugary or fizzy drinks, or acidic foods like fruits or fruit juice until fully recovered.

If you have traveled abroad or there is suspicion that a bacterial or parasitic infection is the cause, your doctor may send off a stool sample – if proven, they will offer antibiotics.

You should contact your doctor urgently if your child is not keeping fluids down and they are not feeding as you would expect. Signs of dehydration include:

• fewer or lighter wet diapers (less than half their normal is worth taking note of and seeking advice on)
• persistent diarrhea or vomiting with no signs of improvement
• crying without tears
• persistent fevers
• increased fussiness
• difficulty waking them or keeping them awake

Blood and mucus in the stool and severe stomach pains need an urgent review by your doctor.