Diarrhoea: causes, how long it lasts and what to do

The NHS says diarrhoea and vomiting can usually be treated at home, and the most important thing is to have lots of fluids to avoid dehydration. NHS inform says most cases clear up after a few days without treatment.

The NHS says diarrhoea usually stops within 5 to 7 days in adults and children, and vomiting usually stops in 1 or 2 days. NHS inform says it normally clears up in a few days to a week.

Both services say to get advice if it goes on for longer than a week. The NHS says to call 111 if you or your child have diarrhoea for more than 7 days or vomiting for more than 2 days.

NHS inform says to drink small sips of water often and to eat as soon as you feel able. It suggests foods that are easy to digest, and low in fibre, and says to avoid fatty or spicy foods.

• white fish, mashed potatoes, yoghurt and jelly

• low-fibre foods such as white bread, white pasta, white rice, plain biscuits and plain cereals

• water or squash in small, regular sips

• avoid fruit juice and fizzy drinks (NHS)

• avoid fatty or spicy foods (NHS, NHS inform)

The NHS says diarrhoea and vomiting can spread easily. Stay off school or work until you have not been sick or had diarrhoea for at least 2 days, and if you have a high temperature or do not feel well, stay at home and avoid contact with others until you feel better. NHS inform advises staying at home until at least 48 hours after the last episode.

• wash your hands with soap and water frequently

• wash clothing or bedding with poo or vomit on it separately on a hot wash

• clean toilet seats, flush handles, taps, surfaces and door handles every day

• do not prepare food for other people, if possible

• do not share towels, flannels, cutlery or utensils

• do not use a swimming pool until at least 48 hours after your symptoms stop

The NHS says the most common causes of diarrhoea and vomiting are a stomach bug and food poisoning. NHS inform says a bowel infection (gastroenteritis) is a common cause in adults and can be caused by a virus such as norovirus or rotavirus, bacteria such as campylobacter and E. coli, or a parasite such as the one that causes giardiasis, which is spread in contaminated water. These infections can be caught while travelling abroad, known as travellers' diarrhoea.

Other causes listed by the NHS include medicines, a food intolerance or allergy, irritable bowel syndrome (IBS), anxiety, appendicitis, inflammatory bowel disease, coeliac disease, diverticular disease and radiation treatment in the pelvic area. NHS inform notes that IBS and inflammatory bowel disease (Crohn's disease and ulcerative colitis) can cause long-term or recurring diarrhoea.

The NHS says dehydration means your body loses more fluid than you take in, and babies, children and older adults are at more risk. Symptoms in adults and children include feeling thirsty, a headache, dark yellow strong-smelling pee, peeing less often, feeling dizzy or tired, a dry mouth, lips and tongue, and sunken eyes.

In a baby, signs may include a sunken soft spot (fontanelle), sunken eyes, few or no tears when crying, fewer wet nappies than usual, and being drowsy or irritable. A pharmacist can recommend oral rehydration powders that you mix with water to replace the sugar, salts and minerals your body has lost.

The NHS gives the same advice for adults and children, with extra points for babies: carry on breast or bottle feeding, give smaller feeds more often if they are being sick, and give small sips of water between feeds if on formula or solid foods.

Call 111 now, according to the NHS, if you are worried about a baby under 12 months, your child stops breast or bottle feeding while ill, or a child under 5 has signs of dehydration such as fewer wet nappies. Do not give children under 12 medicine to stop diarrhoea.

Tommy's, a UK pregnancy charity, says diarrhoea in pregnancy can be caused by hormone changes, a tummy bug or food poisoning, and that it can rarely be caused by an infection such as listeria.

Both Tommy's and the NHS say loperamide (Imodium) is not usually recommended in pregnancy because there is not enough information to say whether it is safe. The NHS advises talking to your doctor before taking it. If you are pregnant and have diarrhoea that is severe, lasts more than a day or two, comes with a fever, or you cannot keep fluids down, contact your midwife, maternity unit, GP or NHS 111.

The NHS says to call 111 now if you or your child have any of the following, and to call 999 or go to A&E for the emergency signs below it.

• blood in diarrhoea or bleeding from the bottom

• diarrhoea for more than 7 days, or vomiting for more than 2 days

• being sick repeatedly and unable to keep fluids down

• signs of dehydration that continue after using oral rehydration sachets

• worry about a baby under 12 months, or a child who stops feeding while ill

• 999 or A&E: vomiting blood or vomit like ground coffee, a stiff neck and pain looking at bright lights, a sudden severe headache or tummy ache, blue, grey, pale or blotchy skin, severe difficulty breathing, or confusion

Most diarrhoea is managed at home or with a pharmacist, who can recommend oral rehydration powder and, for adults, short-term anti-diarrhoea medicine such as loperamide. NHS 111 and the GP are the next step if you meet the warning signs above, and they may arrange a stool sample or blood tests. Diarrhoea that keeps returning or lasts for weeks is a reason to see a GP, who may investigate for conditions such as IBS, coeliac disease or inflammatory bowel disease.