Diarrhoea and vomiting in adults, what to do at home

It is three in the morning, you have lost count of the trips to the bathroom, and the idea of drinking a whole glass of water makes you feel worse. You do not want a lecture about hand hygiene. You want to know what to do in the next few hours.

Nearly all diarrhoea and vomiting in otherwise healthy adults settles on its own. What decides whether you have a rough couple of days or end up genuinely unwell is fluid: how much you lose, and how much you get back in. Everything below is built around that.

No medicine makes a stomach upset disappear. There is, though, a right way and a wrong way to get through it.

The first 24 hours, in order

1. Stop trying to drink normally. Sinking a large glass straight after being sick almost guarantees it comes back up, which is how people end up more dehydrated than when they started.
2. Wait roughly half an hour after vomiting, then take a couple of teaspoons of water every five minutes. Tedious, but it stays down.
3. Once sips are staying put, build up gradually and keep drinking steadily through the day rather than in occasional large amounts.
4. Get oral rehydration sachets from a pharmacy if you can, particularly if the diarrhoea is frequent or you are over sixty. They replace salts and sugars in the proportions that help your gut pull water in.
5. Eat when you genuinely want to, not before. There is no prize for forcing toast down at hour six.
6. Rest near a bathroom and keep half an eye on how often you are passing urine, which is your simplest gauge of whether you are keeping up.
7. Do not reach for anything to block the diarrhoea if there is blood in your stool or you have a high fever. Speak to a doctor first.

What to drink, and what to leave alone

Water is the backbone. Add oral rehydration salts if you have them, and if you do not, a mug of clear broth gives you salt, which is half the problem in heavy fluid loss. Weak squash is fine. Sports drinks are not designed for this and are sugary, but if that is the only thing that will go down, it beats nothing.

Leave full strength fruit juice and sugary fizzy drinks alone while the diarrhoea is active, because that much sugar draws water into your gut rather than out of it. Alcohol and a lot of strong coffee are unhelpful for related reasons, and neither is doing your stomach any favours tonight.

Eating your way back

The old advice to survive on dry toast for days has largely been abandoned, which is a relief. Eating normal food as soon as you can face it helps the lining of your gut repair. Start plain and starchy, since that is what tends to be tolerated: potatoes, rice, pasta, bread, plain crackers, bananas. Salty with starchy sits better than sweet.

Two things catch people out afterwards. Milk and dairy can be harder to digest for a week or two following a gut infection, so if cereal suddenly gives you cramps, that is temporary rather than a new intolerance. Very fatty, spicy or high fibre food also provokes an unsettled gut.

Working out whether you are dehydrated

Thirst is a poor guide here, because nausea blunts it. Use these instead:

• Urine. Passing very little, or going many hours without going at all, is the clearest warning of the lot. Dark urine means you are already behind.
• Standing up. Feeling dizzy, grey or swimmy as you get to your feet suggests your circulating volume is low.
• A dry mouth with no proper saliva, cracked lips, no tears
• Skin that stays tented for a moment when you pinch the back of your hand
• A heart that feels like it is racing while you lie still
• Unusual drowsiness or muddled thinking, often the very first sign in older people

If you are sliding down that list rather than back up it, get advice the same day. Dizziness on standing deserves attention in its own right, and what causes dizziness and how it is treated covers the other reasons it happens.

Time off, and who needs to be more careful

The general rule is to stay away from work, school, the gym and swimming pools until 48 hours after your last episode. That is not squeamishness. You can still pass the infection on when you feel fine again, and it matters most if you handle food for a living, work in healthcare, or look after young children or elderly relatives.

Some people need to treat this more seriously than the average healthy adult:

• If you take medicines for blood pressure, heart failure or diabetes, dehydration can change how they affect you. Ask a doctor what to do while you cannot keep fluids down, and never stop a regular medicine on your own initiative.
• Older adults dehydrate faster and show it later, often as confusion rather than thirst.
• Pregnancy, a weakened immune system, inflammatory bowel disease and recent abdominal surgery all lower the threshold for getting checked.

When to get urgent help

• Passing very little urine, or none at all for many hours
• Dizziness or feeling faint every time you stand up
• Blood in your stool, or stools that are black and tarry
• Symptoms still going beyond a week
• Severe or constant abdominal pain, rather than cramps that ease between waves
• Being unable to keep any fluid whatsoever down for 24 hours
• A high fever, or shaking chills
• Vomit containing blood, or that looks like coffee grounds

Call 999 for severe constant abdominal pain, vomiting blood, or someone who is drowsy and difficult to wake. Call 111 when you need urgent help that is not an emergency: a day without holding fluids down, symptoms dragging past a week, or simply not knowing whether you are dehydrated enough to worry about.

How an online consultation works for this

The practical appeal of a video appointment when you have diarrhoea is obvious, since you never have to be far from your own bathroom. A UK registered doctor will ask how often you are going and what it looks like, whether there is any blood, how much you are managing to drink, what you have eaten recently and whether anyone around you is ill too.

Out of that comes a plan: how to rehydrate properly, what would turn this into something other than a simple gut upset, and a clear point at which to come back. Medicine is prescribed only where it is clinically appropriate, and for many gut infections there is nothing to prescribe, because antibiotics do not touch a virus and can prolong some bacterial diarrhoea. See how the consultation itself works and the fees in pounds, then set up a video appointment when you are ready.

When it is more than a passing bug

Think about the shape of the illness. A sudden upset that peaks within a day or two and then fades is behaving like an infection. Something that never quite settles, keeps returning, or arrived alongside weight loss or blood deserves assessment as a gastrointestinal problem rather than a one-off bug. If it began after one specific meal and others who ate it are ill too, food poisoning and how it is assessed is the better place to start.

If the sips are not going down, or the bathroom trips are not slowing, you probably want to know whether what you are doing is right. Start a consultation and get a plan from a UK registered doctor instead of guessing at three in the morning.