When Does a Stomach Bug Need a Doctor? Gastroenteritis Beyond Rest and Fluids

It is 3 a.m. and the bathroom tiles are cold. You have been sick four times since midnight, your partner is asleep, and the phone in your hand is open to a search bar with the words half typed: when to see a doctor for gastroenteritis. You feel terrible, but you also feel faintly ridiculous. It is just a stomach bug. People get these all the time.

That instinct is mostly right. The large majority of these illnesses run their course without anyone in a white coat. Yet every emergency department sees two kinds of gastroenteritis patient: the person who came in far too early for a self-limiting virus, and the person who waited two days too long while quietly drying out, or while an appendix, a pregnancy or a bowel obstruction wore the costume of a tummy bug.

This article is about telling those situations apart, honestly, using the thresholds that mainstream guidance actually uses rather than folklore passed around at the school gate.

What a stomach bug actually is, and why 'stomach flu' is the wrong name

Gastroenteritis is inflammation of the lining of the stomach and intestines, almost always caused by an infection. The word describes a reaction, not a single germ. Viruses are the usual culprits, with norovirus alone responsible for an estimated 19 to 21 million illnesses a year in the United States according to the CDC. Bacteria such as Salmonella and Campylobacter, bacterial toxins left behind in food, and parasites like Giardia account for the rest.

Whatever the trigger, the mechanics are similar. The infected or irritated lining stops absorbing water properly and often starts secreting it, so fluid pours into the bowel instead of back into the bloodstream. The gut speeds up to flush the problem out, which is diarrhea. Signals from the inflamed stomach and from circulating toxins reach the vomiting center in the brainstem, which is why nausea arrives before anything else. Fever, cramps and that bone-deep weariness are the immune response doing its job.

None of this involves the influenza virus. ‘Stomach flu’ is a nickname, and a misleading one: the flu vaccine offers no protection against norovirus or rotavirus, and influenza itself rarely causes vomiting in adults. The Cleveland Clinic makes the same point plainly.

Typical timing helps set expectations. The Mayo Clinic notes that viral gastroenteritis symptoms usually begin one to three days after exposure, last a day or two, and occasionally drag on for up to 14 days. Norovirus is faster, with symptoms 12 to 48 hours after exposure and lasting one to three days, per the CDC. Those windows matter, because much of the decision about seeing a doctor comes down to whether your illness is behaving the way a routine infection should.

When to see a doctor for gastroenteritis: the short version

If you remember one idea from this article, make it this: the stomach bug rarely hurts people directly. Dehydration does, and so do the conditions that merely look like gastroenteritis. Every reason to see a doctor flows from one of those two risks.

Mainstream guidance converges on a handful of triggers. The NHS advises urgent same-day advice if you keep vomiting and cannot keep fluids down, if there is blood in your stool or bleeding from the bottom, if diarrhea lasts more than seven days or vomiting more than two days, or if signs of dehydration persist after using oral rehydration solution. The Mayo Clinic adds a fever above 104°F (40°C), severe abdominal pain, and an inability to keep liquids down for 24 hours as reasons for adults to seek care.

Layer onto that who you are. A healthy 30-year-old can tolerate a day of vomiting that would put a six-month-old or an 85-year-old in real danger. Pregnancy, diabetes treated with insulin, chronic kidney or heart disease, immunosuppressive medicines and recent travel all lower the threshold for a phone call, not because the virus is different but because the margin for error is thinner.

Then there is the texture of the illness. Routine gastroenteritis is miserable but diffuse: crampy pain that comes and goes, eases after a bowel movement, and is spread across the belly. Pain that settles into one spot, keeps worsening, wakes you at night, or arrives before the vomiting rather than with it is a different story, and clinicians take it seriously.

Everything below expands on these three lenses: how sick, how vulnerable, and how typical. Hold them together and the decision usually becomes clear.

What are the red flags for gastroenteritis in adults?

Dehydration is the quiet emergency, and it rarely announces itself with drama. Early on it looks like unusual thirst, a dry mouth, passing little urine, and urine that has turned dark amber. As it progresses, people feel lightheaded on standing, their heart races, and they may become confused or very drowsy. The Mayo Clinic lists dehydration alongside bloody vomit, blood in bowel movements, severe stomach pain and a fever above 104°F (40°C) as reasons for an adult to see a doctor, together with vomiting that lasts more than two days or an inability to keep liquids down for 24 hours.

Some signs push past ‘see a doctor’ into ‘call emergency services’. The NHS lists vomit that is bloody or looks like coffee grounds, vomit that is green or yellow-green, a stiff neck with pain when looking at bright lights, and sudden severe headache or stomach pain among the reasons to call for emergency help. Coffee-ground vomit suggests digested blood from the upper gut. Green vomit can indicate bile backing up behind a blocked bowel. A stiff neck with light sensitivity raises the question of meningitis, which can begin with vomiting and fever and be mistaken for a bug.

Fainting, chest pain, shortness of breath, or being unable to stand without help also belong in the emergency category. So does an abdomen that is rigid or exquisitely tender to light touch; inflamed gut lining does not usually do that, but a perforated organ does.

Finally, watch the clock as well as the symptoms. Norovirus should be easing within one to three days per the CDC. If you are on day four and getting worse rather than better, the diagnosis deserves a second look even without any single alarming sign.

Red flags in babies, children and older adults

A toddler has a smaller reservoir of water and loses it faster. Globally, the WHO describes diarrheal disease as the second leading cause of death in children under five, with nearly 1.7 billion childhood episodes a year, and dehydration is the mechanism behind almost all of those deaths. In well-resourced settings the outcomes are vastly better, but the physiology is identical.

For infants, the Mayo Clinic advises contacting a doctor for vomiting that is frequent or lasts more than several hours, no wet diaper in six hours, bloody or severe diarrhea, a sunken soft spot on the head, a dry mouth or crying without tears, and unusual sleepiness or unresponsiveness. The NHS adds that any parent worried about a baby under 12 months with diarrhea and vomiting should seek advice, as should parents of a child who stops breast or bottle feeding while ill.

For older children, the Mayo Clinic’s thresholds include a fever of 102°F (38.9°C) or higher, a child who seems unusually tired or very irritable, significant pain or discomfort, bloody diarrhea, and signs of dehydration. The NHS flags dehydration in any child under five as a reason for urgent same-day advice.

Older adults sit at the other end of life with their own vulnerabilities. Thirst sensation blunts with age, kidneys concentrate urine less efficiently, and common prescriptions such as diuretics and blood pressure medicines reduce the body’s ability to compensate for fluid loss. Confusion, a new fall, or simply being ‘not themselves’ can be the first visible sign of dehydration in someone over 75. The same is true for people with dementia, who may not report thirst or nausea at all.

Pregnancy, chemotherapy, organ transplant medicines, long-term steroid use and poorly controlled diabetes also move someone into the ‘call earlier’ group.

Viral or bacterial stomach bug: can you tell at home?

Honestly, not reliably. Clinicians cannot either without a stool test, and most of the time they do not need to, because the first-line management of both is the same: replace fluids and salts, rest, and watch for danger signs.

There are patterns, though, and they matter when deciding whether a test is worth doing. Viral gastroenteritis tends to start abruptly with vomiting, produce watery rather than bloody diarrhea, cause a modest fever, and settle within one to three days. Bacterial infections more often bring high fever, blood or mucus in the stool, severe cramping, and a course that stretches past the usual viral window. Blood in diarrhea is the single clue that most changes a clinician’s thinking, because it points toward invasive bacteria such as Shigella, Campylobacter, Salmonella or Shiga toxin-producing E. coli.

Timing since a suspect meal offers another hint, drawn from the CDC’s summary of food poisoning symptoms:

Likely cause	Typical time from exposure to symptoms	Common features
Staphylococcus aureus toxin	30 minutes–8 hours	Sudden vomiting and cramps, usually brief
Norovirus	12–48 hours	Vomiting, watery diarrhea, lasting 1–3 days
Salmonella	6 hours–6 days	Diarrhea, fever, cramps
Campylobacter	2–5 days	Diarrhea, often bloody, fever, cramps
E. coli O157 (STEC)	3–4 days	Severe cramps, bloody diarrhea, often little fever

Notice how rarely the last meal is to blame. Someone vomiting at midnight after dinner is more likely reacting to something from the day before, or to a virus caught from a doorknob.

Why does the distinction matter if treatment starts the same? Because the exceptions are serious. Some bacterial infections warrant antibiotics in specific circumstances, while in STEC infection antibiotics are generally avoided because they may increase the risk of a kidney complication called hemolytic uremic syndrome. That is a decision for a clinician holding a stool result, never a guess made at home.

What can be mistaken for gastroenteritis?

Nausea, vomiting and belly pain are among the least specific symptoms in medicine. Several conditions borrow them, and the point of listing them is not self-diagnosis but understanding why a clinician may ask questions that seem unrelated to a stomach bug.

Appendicitis is the classic imposter, especially in children and young adults. It often begins with vague central discomfort and a little nausea, then migrates to the lower right abdomen and becomes constant and worsening. Pain that intensifies with movement, coughing or a bumpy car ride is unlike the come-and-go cramps of an infection.

Bowel obstruction causes vomiting, sometimes green with bile, together with a swollen abdomen and an inability to pass gas or stool. People with previous abdominal surgery or hernias are at higher risk. Pancreatitis produces severe upper abdominal pain boring through to the back, frequently with vomiting, and is more common after heavy alcohol use or in people with gallstones.

An ectopic pregnancy, where a pregnancy develops outside the womb, can present with pelvic pain, nausea and lightheadedness in anyone who could be pregnant. Diabetic ketoacidosis, a dangerous build-up of acids when the body lacks insulin, commonly starts with vomiting and abdominal pain; in someone with diabetes, a ‘stomach bug’ with deep rapid breathing and extreme thirst needs urgent assessment.

Heart attacks, particularly in women, older adults and people with diabetes, sometimes announce themselves as nausea, sweating and upper abdominal discomfort rather than chest pain. Meningitis can open with vomiting and fever before the stiff neck appears. Urinary infections in young children, inflammatory bowel disease flares, medication side effects, and Clostridioides difficile infection after a recent course of antibiotics round out the list.

The MedlinePlus overview is right that gastroenteritis is usually mild and self-limiting. The job of a good clinician is to make sure that reassurance is earned.

What is the 48-hour gastro rule?

The 48-hour rule is an infection-control guideline, not a severity timer, and it is widely misunderstood in both directions.

The NHS advises staying off work, school or nursery until you have not been sick or had diarrhea for at least two days, that is, 48 hours after the last episode. The reasoning is simple: you remain infectious after you start feeling human again. The CDC notes that people with norovirus can continue to shed the virus and spread it for two weeks or more after symptoms resolve, with the heaviest shedding in the first days. The 48-hour window is a practical compromise that catches the most contagious period without keeping everyone home for a fortnight.

The first misreading is treating it as a waiting period before seeking help, as in ‘you are supposed to give it 48 hours.’ No guideline says that. The thresholds for calling a doctor are about fluids, blood, pain and duration, and some of them are measured in hours, not days. A baby with no wet diaper for six hours should not wait for a 48-hour anything.

The second misreading is going back to work after 48 hours and relaxing all other precautions. The NHS also advises against swimming in public pools for two weeks after symptoms stop, because tiny amounts of stool contamination can infect a whole pool, and against preparing food for others while ill. Norovirus is notoriously resistant to alcohol hand sanitizer; the CDC is explicit that sanitizers do not work well against it and that soap and running water are the reliable option. Wash contaminated clothing and bedding on a hot cycle, clean surfaces with a bleach-based product, and do not share towels.

Think of the rule as the minimum courtesy you owe colleagues and classmates, layered on top of hand hygiene that continues for days afterward.

Who is usually managed at home, and who is usually asked to come in

Clinicians sort gastroenteritis patients less by how dramatic the vomiting is and more by physiological reserve and risk of an alternative diagnosis.

Home care is the default for a previously healthy adult or older child who can keep sips of fluid down between episodes, is passing urine, has no blood in vomit or stool, has no severe or localized pain, and is roughly following the expected arc of improvement. The NHS frames this group clearly: rest, drink plenty of fluids, eat when able, and seek advice only if the specific thresholds are crossed. A pharmacist can often advise on oral rehydration solution, which is salts and glucose in carefully balanced proportions designed to be absorbed even by an inflamed gut.

People usually asked to come in, or at least to call early, include infants under 12 months, anyone over roughly 65 with other health conditions, pregnant people, those on insulin or on medicines that affect kidney function or blood pressure, anyone immunocompromised, people recently returned from travel to regions where parasites and typhoid are common, anyone who has taken antibiotics in the past few months, and anyone whose symptoms began during a known outbreak in a care home, hospital or cruise ship.

Children follow a particular pathway. Younger children dehydrate quickly, cannot always describe pain, and may need to be observed while a parent offers small volumes of oral rehydration solution under supervision. That is often all the ‘treatment’ is: a quiet room, a syringe or spoon, a few hours, and regular reassessment. Bringing a child’s usual cup, a comfort object and a change of clothes makes that stretch easier. Parents should expect questions about the number of wet diapers, whether the child has tears, and how alert they seem compared with normal.

Being asked to wait is not dismissal. For routine viral illness, time and fluids are the active ingredients, and watching at home with clear instructions about when to return is sound medicine.

What actually happens at the appointment or emergency department

Demystifying the visit removes one reason people delay. Expect the encounter to be built around three questions: how dry are you, is this really gastroenteritis, and does anything need a test?

The history comes first. You will be asked when symptoms began, what came first, whether anyone else is ill, what you have eaten, whether you have traveled, what medicines you take, and, for anyone who could be pregnant, the date of the last period. The clinician will press on your abdomen, listen for bowel sounds, check your temperature, pulse and blood pressure, often lying and then standing, because a pulse that jumps or a pressure that drops on standing is an objective marker of fluid loss. Children are weighed, since weight change is the most accurate measure of dehydration in small bodies.

Tests are selective. Most people with uncomplicated viral illness need none. A stool sample is typically requested when there is blood or mucus, high fever, severe illness, recent travel, recent antibiotics, immunosuppression, or a suspected outbreak, because the result changes decisions about antibiotics and public health notification. Blood tests to check electrolytes and kidney function are common in the very young, the elderly, and anyone who looks significantly dehydrated. Imaging is reserved for cases where an alternative diagnosis is suspected.

Treatment usually starts with a supervised trial of oral rehydration solution in small, frequent volumes. If vomiting prevents that, a clinician may consider an anti-nausea medicine from the antiemetic class to allow oral fluids to stay down, particularly in children; the choice and whether to use one at all sits with the treating team. Intravenous fluids are used when oral rehydration fails or when someone arrives severely dehydrated or confused.

Before discharge you should leave with explicit return criteria. If you do not receive them, ask.

Medicines for a stomach bug: what helps, what does not, and what can harm

The most effective treatment for gastroenteritis is not a drug. Oral rehydration solution works because the gut has a transport system that absorbs sodium and glucose together, dragging water along with them, and that system keeps functioning even when the lining is inflamed. Plain water replaces volume but not salts; sugary soft drinks and undiluted juice can worsen diarrhea by pulling water into the bowel. The WHO identifies oral rehydration as the cornerstone of diarrheal management worldwide, and in children in low-resource settings also recommends zinc supplementation under clinical guidance.

Antidiarrheal agents such as loperamide slow intestinal movement. They can reduce the number of trips to the bathroom in an adult with uncomplicated watery diarrhea, but they are generally avoided when there is blood in the stool or a high fever, because slowing transit can keep invasive bacteria and their toxins in contact with the gut longer. They are not routinely used in young children. Whether one is appropriate for you is a question for a pharmacist or clinician, not a given.

Antiemetics reduce nausea and vomiting through receptors in the gut and brainstem. In pediatric emergency care a single dose of an antiemetic is sometimes used to help a child tolerate oral rehydration, a decision made and dosed by the treating clinician.

Antibiotics do nothing against viruses, which cause the majority of cases. For specific bacterial infections, confirmed or strongly suspected, they may shorten illness or prevent complications in high-risk patients. For Shiga toxin-producing E. coli they are generally avoided. This is precisely why self-prescribing leftover antibiotics is a bad idea.

Probiotics are heavily marketed. The evidence is mixed and strain-specific, and major guidance does not treat them as a standard component of care. If you take regular medicines, especially for diabetes, blood pressure or kidney conditions, ask your prescriber how to handle them during a day or two of poor intake rather than deciding alone.

What the next days and weeks usually look like

Day one is usually the worst. Vomiting dominates, appetite vanishes, and the goal is modest: a few sips every few minutes rather than a glass every hour, since small volumes are more likely to stay down. According to the NHS, vomiting typically stops within one to two days, while diarrhea usually clears within five to seven days in adults and children alike.

By day two or three most people with a viral illness turn a corner. The CDC’s one-to-three-day course for norovirus is a useful benchmark: if you are still vomiting on day three, or still deteriorating, that is your cue to call. Appetite tends to return before the bowels settle fully. Eat when hungry, starting with whatever appeals and is easy to digest; there is no evidence that a rigid ‘white food only’ diet speeds recovery, and prolonged fasting delays the repair of the gut lining.

Through the first week, loose stools may linger even as you feel well. The 48-hour rule governs the return to work and school. Hand hygiene with soap continues to matter for at least two weeks, and the NHS advises avoiding public pools for two weeks after symptoms stop.

Some aftereffects are common and usually temporary. The enzyme that digests lactose lives on the tips of the intestinal lining, which takes the brunt of the damage, so dairy may cause bloating or loose stools for a week or two before tolerance returns. Fatigue can outlast the gut symptoms by several days.

A minority of people develop longer-term bowel symptoms after an infection, a pattern clinicians call post-infectious irritable bowel syndrome, and certain bacterial infections are occasionally followed by joint inflammation known as reactive arthritis. Neither is a reason for alarm during the acute illness, but persistent changes beyond a few weeks deserve a routine appointment, as does weight loss or any recurrence of blood.

What people often get wrong about stomach bugs

Myths cluster around gastroenteritis because almost everyone has had one and almost everyone has advice. A few deserve direct correction.

‘Starve it out.’ The old instinct to withhold food has no support in current guidance. The NHS recommends eating when you feel able, and children in particular should return to their usual diet as soon as they are keeping fluids down. The gut lining heals faster when it has something to work with.

‘Stop the diarrhea at all costs.’ Diarrhea is partly the body flushing out pathogens. Antidiarrheals have a place for some adults with watery illness, but with blood or high fever they can do harm, and they are not a substitute for rehydration.

‘A sports drink is the same as oral rehydration solution.’ It is not. Sports drinks typically contain more sugar and less sodium than rehydration solutions, which is why guidance from the NHS and WHO points to proper oral rehydration products, especially for children and older adults.

‘It must have been the last thing I ate.’ The CDC’s incubation ranges show how often that reasoning fails. Only a few toxin-mediated illnesses strike within hours; most infections take a day or more to declare themselves.

‘I had my flu shot, so this cannot be a stomach bug.’ Influenza vaccines target influenza. Norovirus and rotavirus are unrelated.

‘Hand sanitizer is enough.’ Against norovirus, the CDC is clear that alcohol sanitizers do not work well. Soap, water and twenty seconds of scrubbing remain the standard.

‘Antibiotics will clear it faster.’ For viral illness they are useless and they disrupt the gut flora, raising the risk of a second, nastier infection with C. difficile.

‘The 48-hour rule means wait 48 hours before worrying.’ It means stay home for 48 hours after the last symptom. Danger signs are measured in hours.

Questions to ask your care team

A visit for gastroenteritis is often brief, and it is easy to leave without the information you actually needed. The following questions are the ones patients most regret not asking.

• What signs would mean I should come back or call emergency services, and over what timeframe?
• Based on what you have found today, how confident are you that this is gastroenteritis rather than something else, and what would change your mind?
• Do I need a stool test, and if so, how will I receive the result and what might it change?
• How much fluid should I be aiming for, and how will I know I am keeping up with losses?
• Should I use an oral rehydration solution, and is plain water enough once I am improving?
• I take regular medicines; are there any I should ask my prescriber about while I am not eating or drinking normally?
• Is there any role for an anti-nausea or antidiarrheal medicine in my case, and what are the reasons for or against?
• When can I safely return to work or school, and are there extra precautions for my household, especially for a baby, an older relative or someone with a weakened immune system?
• For a child: what number of wet diapers or trips to the toilet should I expect, and what does ‘too sleepy’ look like at this age?
• Should this be reported to public health, for example because I work in food preparation or care, or because others are ill?
• If I am not better by a particular day, who do I contact and how?

Write the answers down or ask for them in writing. Dehydration and exhaustion are not conducive to memory, and the person caring for you at home will need the same information. Whatever you are told, the specifics of your plan belong to the clinician who has examined you, and they should be revisited if anything changes.

When to call your doctor

Here is the consolidated list, drawn from NHS and Mayo Clinic guidance. It is not exhaustive, and a strong gut feeling that something is wrong is itself a reason to pick up the phone.

Call emergency services or go to the emergency department now if you or the person you are caring for vomits blood or material resembling coffee grounds; vomits green or yellow-green fluid; has sudden severe abdominal pain or a rigid, intensely tender belly; has a stiff neck with pain on looking at bright light or a sudden severe headache; is confused, extremely drowsy, floppy or hard to wake; has fainted or cannot stand without help; has chest pain or breathing difficulty; or, in a baby, has a sunken soft spot, is unresponsive, or has had no wet diaper for six hours or more.

Seek urgent same-day medical advice for an inability to keep fluids down for 24 hours or repeated vomiting that prevents drinking; blood or mucus in the stool; signs of dehydration that persist despite oral rehydration solution; vomiting lasting more than two days or diarrhea lasting more than seven; a fever above 104°F (40°C) in an adult or 102°F (38.9°C) or higher in a child; any baby under 12 months with diarrhea and vomiting; a child who refuses breast or bottle feeds; a child under five with any sign of dehydration; and illness in someone who is pregnant, over 65 with other conditions, taking insulin, immunocompromised, or recently returned from travel.

Book a routine appointment for bowel symptoms that persist beyond a few weeks after recovery, unexplained weight loss, or symptoms that keep returning.

None of these lists replaces clinical judgment. The person who examines you may decide you need nothing more than fluids and time, or may want tests you had not anticipated. Either way, the decision rests with your treating team, and calling early is never the wrong move when you are unsure.

Frequently asked questions

What are the red flags for gastroenteritis?

The main red flags are signs of dehydration, blood in vomit or stool, severe or one-sided abdominal pain, inability to keep fluids down for 24 hours, a very high fever, and symptoms lasting longer than the typical course. Green or coffee-ground vomit, a stiff neck, confusion or fainting are emergency signs. In babies, no wet diaper for six hours, a sunken soft spot, or unusual drowsiness warrant same-day care.

What is the 48-hour gastro rule?

It is the NHS recommendation to stay away from work, school or nursery until 48 hours after your last episode of vomiting or diarrhea, because you remain infectious after you feel better. It is a rule about protecting others, not a waiting period before seeking help. Danger signs such as dehydration in a child or blood in the stool should prompt a call regardless of how many hours have passed.

What can be mistaken for gastroenteritis?

Appendicitis, bowel obstruction, pancreatitis, ectopic pregnancy, diabetic ketoacidosis, meningitis, heart attack, urinary infections in children, inflammatory bowel disease and C. difficile infection after antibiotics can all begin with nausea, vomiting or abdominal pain. Pain that localizes to one spot, steadily worsens, or arrives before vomiting, and vomiting that is green or bloody, are the features that most often prompt clinicians to look beyond a simple stomach bug.

How can I tell if my stomach bug is viral or bacterial?

You usually cannot tell with certainty at home, and neither can a clinician without a stool test. Viral illness tends to start abruptly with vomiting, produce watery diarrhea and settle within one to three days. Bacterial infections more often cause bloody stool, high fever, severe cramps and a longer course. Blood in diarrhea is the clue that most often leads to testing, because it can change decisions about antibiotics.

How long does gastroenteritis last?

According to the NHS, vomiting usually stops within one to two days and diarrhea within five to seven days. The CDC puts norovirus at one to three days, while the Mayo Clinic notes viral gastroenteritis occasionally lasts up to 14 days. Illness that is worsening on day three or four, rather than improving, is a reason to seek medical advice even without a single alarming symptom.

Should I take something to stop the diarrhea?

Not automatically. Antidiarrheal medicines slow the gut and may reduce bathroom trips in adults with uncomplicated watery diarrhea, but they are generally avoided when there is blood in the stool or a high fever, and they are not routinely used in young children. Rehydration matters far more than stopping the diarrhea. Ask a pharmacist or clinician whether one is appropriate in your particular situation.

Do I need antibiotics for a stomach bug?

Usually not. Most gastroenteritis is viral, and antibiotics have no effect on viruses while disrupting the gut’s normal bacteria. For certain confirmed bacterial infections in higher-risk people, a clinician may prescribe them. For Shiga toxin-producing E. coli they are generally avoided because of a possible link to a serious kidney complication. The decision depends on test results and your overall health, and it belongs to your treating clinician.

When should a child with vomiting go to the emergency department?

Go urgently if a child is very drowsy, floppy or hard to wake, has a sunken soft spot, has not had a wet diaper for six hours or more, vomits green or bloody fluid, has severe abdominal pain or a stiff neck, or shows signs of dehydration that do not improve with oral rehydration solution. Any baby under 12 months with vomiting and diarrhea should at least be discussed with a clinician the same day.

Is it safe to eat during a stomach bug?

Yes, once you can keep fluids down. The NHS advises eating when you feel able and returning children to their normal diet promptly rather than restricting them. There is no evidence that fasting or a strict bland diet speeds recovery, and the gut lining heals faster with nutrition. Dairy may cause temporary bloating for a week or two afterward because the enzyme that digests lactose is slow to recover.

How long is gastroenteritis contagious?

You are most infectious while symptomatic and for the first days afterward, which is why the NHS 48-hour rule exists. The CDC notes that norovirus can continue to be shed in stool for two weeks or more after recovery. Thorough handwashing with soap for at least two weeks, avoiding food preparation for others while ill, and staying out of public pools for two weeks after symptoms stop reduce the risk to others.

References

• NHS: Diarrhoea and vomiting
• CDC: About norovirus
• CDC: Symptoms of food poisoning
• WHO: Diarrhoeal disease fact sheet

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.