Key Takeaways

Teething does not cause constipation. There is no mechanism by which a tooth changes how the gut moves stool.

Going several days without a stool is often normal, especially in breastfed babies. Hard, dry pellets — not infrequency alone — define constipation.

Starting solids at the same age teeth arrive is the usual real cause. New foods, especially without enough fluids, firm up stools.

Call the doctor for blood in stool, severe pain, vomiting with a swollen belly, or a newborn who is not passing stool as expected.

The short answer: no

Teething does not cause constipation. The AAP symptom checker lists what teething does not cause, and gut symptoms are not on the teething list — the largest prospective study of teething symptoms found no link between tooth eruption and stool changes like looseness or increased stool number, and constipation fared no better in later reviews.¹²³ A tooth moves through the gum. It does not change how the intestines move stool.

So why does this belief persist? Because teeth and hard stools show up at the same age, and tired parents connect them. If your baby is drooling, chewing everything, and straining on the changing table, the tooth gets the blame. Usually, something else deserves it. Our teething vs. ear infection vs. cold guide covers the full list of symptoms teething truly causes — and gut changes are not among them.

Why the confusion happens

Three things collide at teething age and make the link feel real.

Solids start at the same age. The first tooth usually appears around 6 months — exactly when most babies start solid foods. New foods, especially low-fiber ones like rice cereal and bananas, firm up stools fast. Parents see a tooth and a hard stool in the same week and connect them. The connector is the calendar, not the tooth. Our starting solids guide walks through first foods that are gentler on little stomachs.

Less fluid means firmer stools. A sore-gummed baby may drink less milk for a few days, and a baby fighting a mild fever or cold loses extra fluid. Less fluid in means drier, harder stool out. Dehydration firms stools — teething does not.

New straining looks alarming. Around 6 to 9 months, babies become aware of their bodies and push dramatically: red face, grunting, legs stiff. This looks like painful constipation even when the stool itself is soft. Straining with a soft stool is a skill problem — the baby is learning to coordinate pushing with relaxing the pelvic floor — not true constipation.

Normal infrequency vs. true constipation

This distinction matters most, and the AAP infant constipation guidance draws it clearly.⁴

Clue	Normal infrequency	True constipation
How it looks	Soft stool, even after several stool-free days	Hard, dry pellets or firm balls; sometimes streaked with blood from small tears
Baby’s comfort	Comfortable between stools; may grunt but passes stool without distress	Crying, arching, refusing feeds, or visible pain when passing stool
Who it hits most	Breastfed babies, who can go many days between soft stools	Often babies recently started on solids or switched formulas
What to do	Nothing — this is normal	Home care below, plus a call to the pediatrician if it persists

The key rule: frequency alone does not diagnose constipation. A breastfed baby who poops once every five days with soft stool is not constipated. A baby who poops daily but passes hard pellets with crying is.

What helps at home

For mild constipation in a baby already on solids, start simple:

Offer fluids. Extra breast milk or formula is the first step for young babies. For babies over 6 months, small amounts of water with meals help; small amounts of prune or pear juice can soften stools.⁴
Move the legs. Bicycle the baby’s legs gently and give extra tummy time. Movement stimulates the gut.
Massage the tummy. Gentle clockwise circles on the belly, following the direction of the intestines, can help get things moving.
Adjust solids. Offer fiber-friendly foods — prunes, pears, peaches, peas — and ease back on constipating foods like rice cereal until stools soften.
Do not use DIY fixes. No laxatives, mineral oil, suppositories, or rectal stimulation without your pediatrician’s direction. Infant dosing is not guesswork, and rectal interventions can injure or mask a real problem.⁴

If home steps do not soften things within a day or two, or you are unsure whether it is true constipation at all, call your pediatrician rather than escalating on your own.

When to call the doctor: the red lines

Call promptly for any of these — none of them is teething:

Blood in the stool, more than a tiny streak, or black stools.
Severe pain: screaming with bowel movements, inconsolable crying, or refusing feeds.
Vomiting plus a swollen or hard belly, which can signal blockage — seek care right away.⁴
A newborn who is not passing stool as expected, especially in the first days of life or with poor feeding and vomiting — this needs prompt evaluation.⁴
Constipation that persists despite fluids and diet steps, or keeps coming back.

Frequently asked questions

Can teething cause constipation?

No. Teething affects the gums and mouth — drooling, chewing, mild crankiness, a slight temperature rise below fever level.¹⁵ It has no mechanism to slow the gut. When constipation arrives with a new tooth, look at diet, fluids, and illness first.⁴

Why is my teething baby straining so hard?

Straining with soft stool is usually about coordination, not constipation. Babies around teething age are learning to push effectively, and they grunt and turn red doing it. True constipation means hard, dry stool plus pain — not dramatic pushing alone.⁴

Can teething cause diarrhea instead?

No. Prospective research found no link between tooth eruption and stool looseness, increased stool number, or vomiting.² Diarrhea during teething is its own illness — watch hydration (wet diapers, tears, energy) and call if it persists.⁶

My baby started solids and got constipated. Is it the teeth or the food?

Almost always the food. New solids — especially rice cereal without enough fruits, vegetables, and fluids — firm stools right at the age teeth appear. Offer prunes, pears, or peaches, add small amounts of water if your baby is over 6 months, and give it a few days before blaming the tooth.⁴

How long without pooping is normal for a breastfed baby?

Several days can be completely normal if the stool is soft when it comes and the baby is comfortable, feeding well, and has a soft belly.⁴ Frequency alone is not constipation. Hard pellets, pain, or blood are what change the picture.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Every baby is different. Always consult your pediatrician with questions about your baby’s symptoms, stools, or health.

American Academy of Pediatrics (HealthyChildren.org), “Teething” (KidsDoc Symptom Checker), by Barton Schmitt, MD, FAAP. Source ↩ ↩²
Macknin ML, Piedmonte M, Jacobs J, Skibinski C, “Symptoms associated with infant teething: a prospective study,” Pediatrics 2000;105(4):747-752. Source ↩ ↩²
Massignan C, Cardoso M, Porporatti AL, et al., “Signs and Symptoms of Primary Tooth Eruption: A Meta-analysis,” Pediatrics 2016;137(3):e20153501. Source ↩
American Academy of Pediatrics (HealthyChildren.org), “Infant Constipation.” Source ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹
Mayo Clinic, “Teething: Tips for soothing sore gums,” published Dec. 21, 2024. Source ↩
American Academy of Pediatrics (HealthyChildren.org), “Fever and Your Baby,” published Sept. 23, 2025. Source ↩