Acute gastroenteritis (diarrhoea and vomiting)
Also called: stomach flu, stomach bug, infectious diarrhoea, food poisoning, loose motions, dast (Urdu)
Acute gastroenteritis is a short-lived infection of the stomach and gut that causes diarrhoea, vomiting and stomach cramps. Most people get better at home with fluids. In children, oral rehydration salts (ORS) and zinc are the main treatment; antibiotics are rarely needed.
General health information for Pakistan. It does not give doses or brand advice. If you are worried, or symptoms are severe, see a doctor. When to see a doctor
Overview
Acute gastroenteritis is an infection that inflames the lining of the stomach and intestines (the gut). It usually starts suddenly with loose or watery stools, vomiting, or both. Diarrhoea means passing three or more loose or liquid stools in a day, or more often than is normal for that person. Many people also have stomach cramps, nausea (feeling sick) and sometimes fever.
Viruses such as rotavirus and norovirus are the most common cause. Bacteria (for example Salmonella, Shigella, Campylobacter and some types of E. coli) and parasites (for example Giardia and amoeba) cause a smaller share of cases but can make people more unwell. The germs spread through contaminated water or food, dirty hands, and close contact with someone who is ill.
In most healthy people the illness is mild and passes on its own. Vomiting usually settles within one to three days and diarrhoea within about a week. The main danger is dehydration (losing too much water and salt from the body), especially in babies, young children, older people and people who are malnourished or have other illnesses. Worldwide, diarrhoeal disease is one of the top three causes of death in children under five, even though almost all of these deaths can be prevented with clean water, good hygiene and simple treatment with oral rehydration salts (ORS) and zinc.
In Pakistan: what studies show
Too few children in Pakistan get the simple treatment for diarrhoea: in Sindh in 2018-2019 only 22% got both ORS and zinc, and across two national surveys only 6.2% got the recommended treatment. Rotavirus vaccine, started in 2017, gave about 33% protection to young babies in a study of 9 hospitals.
- In the 2018-2019 Sindh household survey (MICS), about half (51%) of young children with diarrhoea were given ORS.[1] (survey, data 2018-2019)
- In the same 2018-2019 Sindh survey, only 22% of young children with diarrhoea got both ORS and zinc, the treatment that is recommended.[1] (survey, data 2018-2019)
- A study using Pakistan's two national health surveys (2012-2013 and 2017-2018) found only 6.2% of young children with watery diarrhoea got the recommended treatment, rising from about 1% in the first survey to about 10% in the second.[2] (secondary analysis of national survey data, data 2012-2013 and 2017-2018)
- Pakistan started giving rotavirus vaccine in early 2017; a study in 9 hospitals in 3 provinces from 2018 to 2023 found that two doses gave about 33% protection against rotavirus diarrhoea in babies aged 22 weeks to 11 months.[3] (case-control, data April 2018 - March 2023)
- One hospital study in Karachi (Aga Khan University Hospital) found that of 175 children admitted with watery diarrhoea, 106 (60.6%) were not given antibiotics, which means the rest were, even though most watery diarrhoea does not need them.[4] (cross-sectional, data June 2017 - December 2018)
- One hospital study in Karachi in 2020-2021 found that more than 90% of prescriptions for acute diarrhoea in children under five did not follow treatment guidelines.[5] (cross-sectional, data August 2020 - August 2021)
- An older letter in a Pakistani medical journal (2009) said rotavirus was causing close to 20,000 deaths of children under five in Pakistan each year; this is a second-hand estimate from before the vaccine was introduced.[6] (report, data not stated)
What we do not know yet: We could not open the national Pakistan Demographic and Health Survey report tables, so the share of young children with diarrhoea nationally, and recent UNICEF/IGME or GBD death counts, are not shown here; the only death estimate found (about 20,000 a year) is old and second-hand. No Pakistan IMNCI or national diarrhoea guideline page could be opened, and the antibiotic data come from single hospitals in Karachi.
Pakistan studies cited
- Sindh Bureau of Statistics, Government of Sindh MICS Statistical Snapshot: Child health - care of illness (Sindh Multiple Indicator Cluster Survey 2018-19). Sindh Bureau of Statistics (Sindh MICS 2018-19) 2021. Open source
- Lassi ZS, Karatela S, Syed ARS, et al. Assessing the relationship of recommended diarrhea case management practices with the nutritional status of children aged between 0 to 59.9 months (version 1). Health Open Research 2023;5. Open source
- Ali SA, Sultana S, Riaz A, et al. Effectiveness of monovalent rotavirus vaccine among young children in Pakistan: a test-negative case-control evaluation. Vaccine 2026;81:128555. doi:10.1016/j.vaccine.2026.128555. Open source
- Qureshi S, Resham S, Hashmi M, et al. A retrospective review on antibiotic use in acute watery diarrhea in children in a tertiary care hospital of Karachi, Pakistan. PLoS ONE 2021;16(7):e0253712. Open source
- Siddiqui DS Prescribing Practices of Antibiotics for Acute Diarrhea in Children Aged Less than Five Years Old in Pakistan. Journal of Pharmacy (IIUM) 2022;2(1):8-15. doi:10.31436/jop.v2i1.116. Open source
- Zubair MH, Zubair MM, Riaz H Rota virus mortality: a dilemma for the developing world (letter to the editor). Journal of the Pakistan Medical Association 2009;59(8). Open source
Symptoms
- Sudden loose or watery stools, often several times a day
- Vomiting, which usually starts first and settles within a few days
- Nausea (feeling sick) and loss of appetite
- Stomach cramps or griping pain that comes and goes
- Fever, usually mild
- Tiredness, weakness and body aches
- Signs of dehydration: thirst, dry mouth, passing less urine, dark urine, headache
- In babies: fewer wet nappies, no tears when crying, sunken eyes, unusual sleepiness or irritability
Causes and risk factors
Causes
- Viruses, the most common cause, especially rotavirus in young children and norovirus in all ages; adenovirus and astrovirus also cause it
- Bacteria such as Salmonella, Shigella, Campylobacter and some E. coli types, often from contaminated food or water
- Parasites such as Giardia, Cryptosporidium and Entamoeba (amoeba), usually from unsafe water
- Toxins made by bacteria in food that was stored or prepared unhygienically (food poisoning)
- Less often, a reaction to certain medicines, chemicals or foods
What makes it more likely
- Age under one year, and especially under six months
- Drinking unsafe water or eating food prepared or stored in unhygienic conditions
- Poor handwashing, especially after using the toilet, changing nappies and before handling food
- Close contact with someone who has diarrhoea or vomiting (home, school, hospital)
- Malnutrition, which makes diarrhoea more likely and more severe, and diarrhoea in turn worsens malnutrition
- Babies who are not breastfed or who have stopped breastfeeding
- A weak immune system, pregnancy, older age or other long-term illness
- Recent travel, or living in an area with poor sanitation and crowded housing
Complications
Dehydration is by far the most common and most dangerous complication. The body loses water and salts in the stools and vomit faster than they are replaced. Severe dehydration can cause shock (very low blood pressure), kidney damage, fits and death, especially in babies and small children. Repeated episodes of diarrhoea in children can lead to malnutrition and poor growth. Some bacterial infections can spread into the blood (septicaemia). Certain strains of E. coli can cause haemolytic uraemic syndrome, a rare but serious condition that damages the kidneys. Less commonly, joint pain (reactive arthritis) or nerve weakness (Guillain-Barre syndrome) can follow infections with Campylobacter, Shigella or Salmonella. In some people the gut takes weeks to settle and temporarily cannot digest milk sugar (lactose).
When to see a doctor
- Signs of severe dehydration: very sleepy or hard to wake, cold or mottled hands and feet, fast weak pulse, not passing urine, skin pinch that goes back very slowly, or in babies a sunken soft spot on the head
- Unable to keep any fluid down because of repeated vomiting, or refusing to drink
- Blood or mucus in the stools, or black tarry stools
- High fever, especially in a baby under three months, or fever with neck stiffness, a rash that does not fade when pressed, or confusion
- Green (bilious) vomit, severe or constant stomach pain, or a swollen hard tummy, which may point to a different, serious problem
- Diarrhoea lasting more than a week, or more than two days in a baby or young child
- A baby under six months, a malnourished child, an older person or anyone with a weak immune system who develops diarrhoea and vomiting
Diagnosis
Acute gastroenteritis is usually diagnosed from the story and an examination; no tests are needed in most cases. The doctor or health worker asks when the diarrhoea and vomiting started, how often they happen, whether there is blood in the stool, whether others at home are ill, and about recent food, water and travel. The most important part of the examination is checking for dehydration: how alert the person is, whether the eyes are sunken, how fast the pulse and breathing are, how quickly a pinch of skin goes back, and how much urine is being passed.
A stool sample is sent to the laboratory only in certain situations: blood or mucus in the stool, severe illness or suspected blood infection, a weak immune system, recent travel, diarrhoea not improving after about a week, or when the diagnosis is unclear or an outbreak is suspected. Blood tests for salts (electrolytes), kidney function and sugar are done if the person is severely dehydrated or needs fluids through a drip.
Treatment
- Replace lost fluid early. Keep drinking small amounts often. Children should keep breastfeeding or having their usual milk. Oral rehydration salts (ORS) mixed with clean water exactly as the packet says are the best fluid; avoid fruit juice and fizzy drinks.
- If there are signs of dehydration, give ORS in small, frequent sips over a few hours, by spoon or cup, even if the child is vomiting. A health worker will say how much to give. Diarrhoea and vomiting often settle as the dehydration is corrected.
- For children with diarrhoea, give zinc as a short course alongside ORS, as recommended by WHO and UNICEF. It shortens the illness and lowers the chance of another episode in the following months. Your doctor or pharmacist decides the dose.
- Restart normal food as soon as the person can eat, usually within a few hours of rehydration. Do not starve the gut; the old idea of withholding food for a day or more is harmful. Give extra meals as the child recovers.
- Severe dehydration or shock is an emergency and needs fluids through a vein (a drip) in hospital, then a switch back to ORS by mouth once the person is alert and drinking. Persistent vomiting may be treated with ORS through a feeding tube or, in some cases, an anti-sickness medicine chosen by the doctor.
- Antibiotics are not needed in most cases, because most gastroenteritis is viral and gets better on its own. A doctor may prescribe them only for specific infections such as dysentery (bloody diarrhoea with Shigella), cholera, giardiasis, amoebic dysentery, suspected blood infection, or in babies, malnourished people or people with weak immunity.
- Anti-diarrhoea medicines that slow the gut should not be given to children. In adults they are used only on medical advice and never when there is fever or blood in the stool.
Medicines in Pakistan
Medicines a doctor may use, by group. Each link opens our page for that medicine, with every brand and its official DRAP price. Your doctor decides which medicine and dose are right for you.
| Group | Role | Medicines |
|---|---|---|
| Oral rehydration salts (ORS) | first and most important treatment for everyone with diarrhoea; the low-osmolarity formula recommended by WHO causes less vomiting and less stool output than older formulas | Oral rehydration salts (low-osmolarity), Oral rehydration salts (ORS) (10 brands) |
| Zinc supplements | given to children with diarrhoea alongside ORS as a short course; shortens the episode and reduces further episodes for two to three months; doctor decides the dose | Zinc (62 brands), Zinc sulfate (19 brands), Zinc (elemental) (1 brand) |
| Antiemetics (anti-sickness medicines) | not routine; a doctor may use one for persistent vomiting that is stopping ORS from being taken, to help avoid a drip or hospital admission | Ondansetron (256 brands) |
| Antibiotics | only for specific proven or strongly suspected infections (dysentery, cholera, giardiasis, amoebiasis, blood infection) or for high-risk patients; never routinely, and avoided in some E. coli infections where they can do harm; choice depends on the germ and local resistance | Azithromycin (662 brands), Ciprofloxacin (761 brands), Metronidazole (258 brands) |
| Antimotility (anti-diarrhoea) medicines | not recommended for children; adults may use with caution on medical advice only, and never with fever or bloody stools | Loperamide HCl (30 brands) |
| Rotavirus vaccine | prevention; given to babies as part of routine immunisation to protect against the most common cause of severe diarrhoea in young children | Rotavirus vaccine, live attenuated (2 brands), Rotavirus vaccine, live, oral, pentavalent (1 brand) |
Also used (not yet in our price list): Probiotics: some studies suggest they may slightly shorten diarrhoea, but guidelines do not yet recommend them routinely; ask your doctor
Self-care and prevention
Self-care
- Drink little and often. Water, ORS, milk for children, or soups are suitable; avoid fruit juice, fizzy drinks and very sugary drinks, which can make diarrhoea worse
- Mix ORS with clean (boiled and cooled) water in the exact amount written on the packet. Too little water makes it too strong
- Keep breastfeeding babies throughout the illness, and offer ORS as well if the baby has diarrhoea
- Eat normal food as soon as you feel able to; small, frequent meals are easier. Children should go back to their usual diet and milk straight after rehydration
- Rest, and take paracetamol if needed for fever or cramps; your pharmacist or doctor can advise on the dose
- Wash hands with soap and water after using the toilet, after changing nappies and before preparing or eating food. Do not share towels
- Stay off work, school or nursery until at least 48 hours after the last episode of diarrhoea or vomiting, and avoid swimming pools for two weeks
- Watch for signs of dehydration (less urine, dry mouth, drowsiness, sunken eyes) and seek help early if they appear
Prevention
- Drink safe water: boiled, filtered or from a trusted treated supply, and store it in a clean covered container
- Wash hands with soap after using the toilet, after cleaning a child, and before cooking, serving or eating food
- Cook food thoroughly, eat it fresh, cover leftovers, and keep raw and cooked food apart; be careful with street food and cut fruit in hot weather
- Breastfeed babies exclusively for the first six months and continue alongside other foods afterwards
- Make sure babies receive the rotavirus vaccine with their routine immunisations
- Use a proper toilet or latrine and keep it clean; safe disposal of human waste keeps germs out of water and food
Common questions
Does my child need antibiotics for diarrhoea?
Usually not. Most gastroenteritis is caused by viruses, and antibiotics do nothing against viruses. Guidelines say antibiotics should be given only for certain infections such as bloody diarrhoea due to Shigella, cholera, giardia or amoeba, or to babies and other high-risk patients. Giving antibiotics when they are not needed can cause side effects and drives antibiotic resistance.
How do I make and give ORS?
Use one packet of ORS with the exact amount of clean water printed on the packet, usually boiled and cooled water. Give small sips often with a spoon or cup, even if the child vomits a little; small frequent amounts stay down better. Throw away any solution left after 24 hours and make a fresh one. A health worker can tell you how much your child needs.
Should I stop feeding my child until the diarrhoea stops?
No. Keep breastfeeding during the illness and go back to normal milk and food as soon as the child is rehydrated, usually within a few hours. Withholding food does not help and makes malnutrition more likely. Avoid fruit juice and fizzy drinks until the diarrhoea has stopped.
Why is zinc given to children with diarrhoea?
WHO and UNICEF recommend a short course of zinc for children with diarrhoea in addition to ORS. Zinc shortens the illness, reduces the amount of stool, and lowers the chance of another episode over the next few months. It is safe and cheap, but only a small share of children in Pakistan currently receive it. Your doctor or pharmacist decides the dose.
How long will it last and when can my child go back to school?
Vomiting usually stops within one to three days and diarrhoea within about a week, though it can take up to two weeks to settle fully. Children and adults should stay away from school, nursery or work until at least 48 hours after the last episode of diarrhoea or vomiting, so that they do not pass the infection on.
Sources
- WHO. Diarrhoeal disease (2024).
- WHO eLENA. Zinc supplementation in the management of diarrhoea (2024).
- NICE. Diarrhoea and vomiting caused by gastroenteritis in under 5s: diagnosis and management (CG84) - Recommendations (2009).
- CDC MMWR. Managing Acute Gastroenteritis Among Children: Oral Rehydration, Maintenance, and Nutritional Therapy (2003).
- MedlinePlus. Gastroenteritis | Stomach Flu | MedlinePlus (2022).
- StatPearls (NCBI). Bacterial Gastroenteritis (Archived) - StatPearls - NCBI Bookshelf (2023).
- Life (Basel), via PMC. Assessment of Determinants of Paediatric Diarrhoea Case Management Adherence in Pakistan (2023).
Prepared from the sources listed below by the MedInfoBase team. Last reviewed 16 October 2026. This page is general health information, not medical advice. It gives no doses and does not replace a doctor: talk to your doctor or pharmacist before starting, stopping or changing any medicine. How we write and check our pages.