Teething and Diarrhoea: Is It Really Caused by Teething?

Many parents sit in my clinic completely exhausted, holding a baby who is teething and now has loose stools, and the worry is always the same: “Is this diarrhoea from teething… or is my baby sick?”

You’re not alone in asking this. In my experience, as a primary health care nurse caring for children, this is one of the most common concerns during teething months.

The truth is simple, but often misunderstood.

Teething does not directly cause diarrhoea. Some babies may have slightly looser stools during teething due to increased drooling, chewing, and mild changes in routine; however, true diarrhoea is usually caused by a viral infection, a bacterial infection, or dietary changes—not teething itself.

What parents usually notice during teething

Teething is a busy time for babies. Gums are sore, sleep is disturbed, and everything goes into the mouth.

One of the most common concerns I hear from parents is the following:
“My baby was fine, then teething started, and suddenly the nappies changed.”

What often happens around teething includes the following:

• More drooling than usual
• Chewing on fingers and objects
• Slightly looser stools (not always diarrhoea)
• Fussiness and disrupted sleep
• Mild temperature increase

Unsure if teething causes fever? Read: Can Teething Cause Fever? What Parents Need to Know

But here is what matters: these changes often happen at the same time as normal developmental exposure to germs.

So teething gets blamed for everything that is actually happening alongside it.

So can teething cause diarrhoea?

Let’s be very clear and honest here.

Teething itself does not cause true diarrhoea.

In my clinical experience, when a baby has frequent watery stools (especially more than 3–6 times in a day), it is almost always due to something else, such as:

• Viral gastroenteritis (very common in babies and toddlers)
• Bacterial infection
• Changes in formula or diet
• Food intolerance
• Antibiotics
• Poor hand hygiene leading to infections

Teething may coincide with these, but it is not the cause.

Why parents think teething causes diarrhoea

There are a few very understandable reasons for this confusion.

1. Increased drooling

During teething, babies produce a lot of saliva. When they swallow more saliva, stools can look slightly softer.

This is often mistaken for diarrhoea.

2. Everything goes into the mouth

Babies explore the world orally during teething. This increases exposure to viruses and bacteria.

So while teething is happening, the risk of infection is also higher.

3. Timing coincidence

Teething often starts around 6–24 months, which is also the age when babies start solids and get more exposure to germs.

So parents naturally connect the two.

What true diarrhoea looks like

Parents need to know the difference between normal stool changes and real diarrhoea.

Diarrhoea usually includes the following:

• Very watery, frequent stools
• Sudden increase in number of nappies
• Strong smell compared to usual
• Possible vomiting
• Signs of dehydration (dry mouth, fewer wet nappies)

Diarrhoea in babies is usually caused by infection and should always be monitored closely.

When it is NOT diarrhoea (but normal teething changes)

You are more likely dealing with teething-related changes if:

• Stool is only slightly softer than normal
• The baby is otherwise well and alert
• Feeding is normal
• Wet nappies are still regular
• There is no vomiting or fever

This is where reassurance is important. Not every nappy change means illness.

Read the full post on: Teething in Babies: The Complete Nurse’s Guide to Symptoms, Myths, Relief & When to Worry

What else could be causing diarrhoea at the same time?

This is where I always encourage parents to widen the lens a little.

Teething often gets blamed, but these are the real common causes:

Viral infections

These are the most common causes in young children. They spread easily through hands, toys, and surfaces.

Food changes

Introducing new foods or juices can temporarily upset the gut.

Formula issues

Switching formula or incorrect mixing can cause loose stools.

Antibiotics

These can disturb gut bacteria and lead to diarrhoea.

Poor hygiene exposure

Babies crawling and putting toys in their mouths are constantly exposed to germs.

What you can do at home

Most mild cases can be managed safely at home, but observation is key.

Keep your baby hydrated

Offer frequent breastfeeds or formula feeds. If older than 6 months, small amounts of oral rehydration solution may be used if advised by a healthcare professional. Home care for diarrhoea can prevent hospitalisation.

Watch wet nappy

This is one of the most important indicators. Your baby should still be passing urine regularly.

Keep feeding simple

Avoid introducing new foods while stools are loose.

Soothe teething discomfort

• Chilled teething rings
• Gentle gum massage
• Extra comfort and cuddles

Maintain hygiene

Wash hands regularly and clean toys to prevent the spread of infection.

When to worry and seek medical help

This is the part I always emphasise in clinic, because early care prevents complications.

Seek medical attention if your baby has:

• Persistent watery diarrhoea (more than 24–48 hours)
• Blood or mucus in stool
• Signs of dehydration (sunken eyes, dry lips, very few wet nappies)
• High fever
• Vomiting that prevents feeding
• Extreme lethargy or unusual sleepiness
• Diarrhoea in a baby under 3 months

Trust your instincts. If your baby is not behaving like themselves, it is worth getting them checked out. Not sure when to take your baby to hospital? Read: Clinic or Hospital for a Sick Baby? Emergency Warning Signs Parents Should Know

In my experience as a Primary Health Care Nurse…

I often see parents feel guilty or confused, thinking they “missed” something or blamed teething too quickly.

One of the most reassuring things I can say is this: most babies with teething and mild stool changes are completely fine. But when it is diarrhoea, it usually has a clear cause that needs attention.

Your role is not to diagnose—it is to observe patterns and act when something feels off.

Frequently asked questions

Can teething cause explosive diarrhoea?

No. Explosive, watery diarrhoea is almost always infection-related, not teething.

How long does teething diarrhoea last?

Teething does not cause diarrhoea. If your baby has diarrhoea lasting more than 1–2 days, it should be assessed.

Why does my baby get diarrhoea every time they teethe?

It may not be teething. It is more likely repeated viral exposure or diet-related changes.

Can teething cause fever and diarrhoea together?

Mild temperature changes can occur with teething, but fever with diarrhoea usually suggests infection.

Should I stop feeding during diarrhoea?

No. Continue feeding. Hydration is essential. Seek medical advice if feeding is difficult.

If you found this post helpful, you might also like:

Baby Not Eating During Teething: What’s Normal, What’s Not, and When to Worry

Teething vs Illness: How to Tell the Difference

TEETHING IN BABIES: SYMPTOMS – WHAT’S NORMAL VS NOT