Diarrhoea Treatment: What to Take and When to See a Doctor

When Your Gut Rebels

Acute diarrhoea — loose, watery stools three or more times a day — is one of the most common reasons people visit a pharmacy. Most cases are caused by viral gastroenteritis (a "stomach bug") and resolve within 2-3 days without treatment.

But knowing what to do (and what not to do) makes a significant difference to how quickly you recover.

Priority One: Rehydration

The biggest risk from diarrhoea isn't the diarrhoea itself — it's dehydration. You lose water and essential salts (electrolytes) with every loose stool. Replacing them is the most important thing you can do.

Signs of Dehydration

• Thirst, dry mouth, dry lips
• Dark yellow urine (or not urinating)
• Dizziness or lightheadedness
• Headache
• Fatigue
• In children: fewer wet nappies, no tears when crying, sunken eyes

What to Drink

• Water — sip frequently rather than gulping large amounts
• Oral rehydration solutions (ORS) — such as Dioralyte, which provides the precise balance of salts and glucose your body needs
• Clear broths — provide sodium and are easy on the stomach
• Diluted fruit juice — provides some sugar and potassium

What to Avoid

• Fizzy drinks — high sugar content can worsen diarrhoea (osmotic effect)
• Alcohol — dehydrating
• Caffeine — stimulates the gut and is mildly dehydrating
• Milk — temporary lactose intolerance is common during gut infections

Dioralyte

Dioralyte sachets are the pharmacist's first recommendation for diarrhoea. They contain a precise WHO-recommended formula of sodium, potassium, and glucose that your gut absorbs efficiently even when inflamed.

Available in natural and blackcurrant flavours. Dissolve one sachet in 200ml of water and drink after each loose stool.

When to Use Anti-Diarrhoeal Medication

Imodium (Loperamide)

Loperamide slows down gut motility, allowing more water to be absorbed from the stool. It's effective and safe for short-term use in adults.

When to use it:

• You need to function normally (work, travel, important events)
• Diarrhoea has persisted for more than 24 hours with no improvement
• There's no fever or blood in the stool

When NOT to use it:

• Blood or mucus in your stool
• High fever (>38.5°C)
• Suspected food poisoning with vomiting
• Children under 12 (without medical advice)
• Diarrhoea caused by antibiotics (could worsen C. difficile infection)

Imodium Instants dissolve on the tongue without water — convenient when you're not near a drink.

How to Take Imodium

• Take 2 capsules/tablets initially
• Then 1 after each loose stool
• Maximum 6 in 24 hours for adults
• Stop once stools are firm — don't continue "just in case"

What to Eat

The First 24 Hours

Many people don't feel like eating, and that's fine. Focus on fluids. When you are ready to eat:

• Plain toast or crackers — easy to digest
• White rice — binding effect
• Bananas — replace potassium
• Boiled potatoes — gentle on the stomach
• Clear soup/broth — hydrating and nutritious

What to Avoid While Recovering

• Fatty or fried foods
• Dairy products (temporary lactose intolerance is common)
• Spicy foods
• High-fibre foods (wholegrain bread, raw vegetables)
• Sugary foods and drinks

After Recovery

Reintroduce normal foods gradually over 2-3 days. A probiotic supplement can help restore healthy gut bacteria, particularly after gastroenteritis.

When to See a Doctor

Most diarrhoea resolves on its own. See your GP or call 111 if:

• Diarrhoea lasts more than 7 days (or more than 5 days in elderly)
• Blood or black stools
• High fever (>38.5°C) alongside diarrhoea
• Severe abdominal pain (not just cramping)
• Signs of significant dehydration (confusion, rapid heart rate, not urinating)
• Recent travel to areas with tropical infections
• Recent antibiotic use (risk of C. difficile)
• You're immunocompromised or have a chronic illness
• Children under 5 or adults over 65 with persistent symptoms

Go to A&E If:

• Bloody diarrhoea with high fever
• Signs of severe dehydration (confusion, inability to keep fluids down)
• Severe, worsening abdominal pain

Preventing Spread

Gastroenteritis is highly contagious. To protect others:

• Wash hands thoroughly with soap and water (alcohol gel is less effective against norovirus)
• Don't prepare food for others until 48 hours after symptoms stop
• Don't share towels
• Clean bathrooms with bleach-based products
• Stay home from work/school until 48 hours symptom-free

Your Pharmacy Toolkit

For a standard stomach bug, keep these in your medicine cabinet:

1. Dioralyte sachets — rehydration (priority)
2. Imodium Instants — symptom control when needed
3. Paracetamol — for any associated headache or fever

Browse our Digestive Health collection for these and other pharmacy essentials.