should I use Gaviscon or a thickener for baby reflux?

Both are roughly equivalent for reducing visible spit-up — the key head-to-head study (Del Buono 2005) found no significant difference in reflux frequency, duration, or acid clearance. Choose based on practicality: thickeners are more adjustable and have lower constipation risk; Gaviscon comes in pre-measured sachets and is easier to dose consistently.

does Gaviscon Infant work for silent reflux?

Evidence is weak. The 2005 Del Buono trial found that Gaviscon only significantly reduced how far up the oesophagus reflux traveled — not how often it happened or how long acid contact lasted. For silent reflux, where the problem is acid irritation rather than visible spit-up, the real escalation is acid suppression medication (omeprazole) via your pediatrician.

what is the difference between Gaviscon Infant and feed thickeners?

Gaviscon Infant forms a physical gel raft on top of stomach contents to block reflux. Thickeners (like locust bean gum or Carobel) increase the viscosity of the milk, making it harder to reflux. Both work mechanically, not by reducing acid. Gaviscon has higher constipation risk due to aluminum. Thickeners require measuring and mixing but are more adjustable.

how long should I try Gaviscon or thickeners before going back to the doctor?

2 weeks of consistent use is a fair trial. If you are seeing no improvement in feed comfort, sleep, or baby's distress after 2 weeks — or if weight gain is faltering, feed aversion is developing, or sleep disruption remains severe — escalate to your pediatrician to discuss acid suppression medication.

can I use Gaviscon and a thickener at the same time?

There is no strong evidence for combining them, and the practical risks increase — constipation risk is higher with Gaviscon, and adding a thickener can make feeds very thick, requiring nipple size adjustment. Most guidelines recommend trialling one at a time so you can assess what is actually helping.

Gaviscon vs Thickeners: An Evidence-Based Comparison

Your pediatrician might suggest Gaviscon. Your health visitor might suggest a thickener. The internet will tell you both are miracle cures. Here’s what the studies actually show.

How Gaviscon Infant Works

Gaviscon Infant contains sodium alginate and magnesium alginate. Mixed into a feed, it forms a viscous gel “raft” that sits on top of stomach contents. The theory: this raft physically blocks stomach contents from refluxing back up the esophagus.

It’s not an antacid in the traditional sense — it doesn’t reduce acid production. It’s a mechanical barrier.

How Feed Thickeners Work

Feed thickeners — typically locust bean gum (johannesbroodpitmeel/carob bean gum), rice cereal, or commercial products like Carobel — increase the viscosity of the milk. Thicker liquid is harder to reflux. Simple physics.

Like Gaviscon, thickeners don’t address acid production. They reduce the visible symptom (spit-up) through mechanical means.

The Head-to-Head: Del Buono 2005

The most direct comparison is Del Buono et al. (2005), published in the Archives of Disease in Childhood (PMC1720405). Here’s what they actually found:

Study design: Randomized crossover trial. 20 infants with proven gastroesophageal reflux (confirmed by pH probe). Each infant received both Gaviscon Infant and Carobel (locust bean gum thickener) for one week each, with pH monitoring.

Results:

Measure	Gaviscon	Carobel	Significant?
Reflux index (% time pH <4)	No significant change	No significant change	No
Number of reflux episodes	No significant change	No significant change	No
Episodes lasting >5 minutes	No significant change	No significant change	No
Reflux height	Reduced	Not reduced	Yes (p<0.05)

Read that again. The only statistically significant difference was reflux height — how far up the esophagus the refluxate traveled. Not how often reflux happened. Not how long it lasted. Not how acidic it was.

Sample size: 20 infants. This is a tiny study. The confidence intervals are wide enough to drive a truck through.

Clinical significance: Even the one positive finding (reflux height) is of questionable clinical relevance. If your baby is still refluxing the same number of times, for the same duration, with the same acidity — does it matter that the refluxate traveled slightly less far up the esophagus? Maybe. But it’s not the slam dunk that Gaviscon marketing might imply.

The Thickener Evidence: Buts 1987

Buts et al. (1987, PMID 3032640) studied sodium alginate (essentially, Gaviscon) in 20 infants with GER. Key finding: vomiting episodes decreased from a median of 5.3 to 2.1 per day (p<0.001). That’s a meaningful clinical reduction in visible vomiting.

However — and this is critical — pH-probe measurements showed no change in acid reflux. The babies vomited less, but their esophageal acid exposure was unchanged.

This is the fundamental limitation of both approaches: they reduce what you can see (spit-up, vomiting) without addressing what you can’t see (acid irritation).

For Silent Reflux Specifically

This is where both options hit a wall. Silent reflux, by definition, involves minimal visible regurgitation. The baby’s problem is acid irritation without spit-up.

Both Gaviscon and thickeners primarily reduce visible regurgitation. If your baby doesn’t visibly spit up much anyway, neither treatment is targeting the actual problem.

This doesn’t mean they’re useless — there may be micro-reflux events that thickening reduces — but the evidence base is built on measuring visible symptoms, not the subtle acid irritation that characterizes silent reflux.

Practical Comparison

Factor	Gaviscon Infant	Feed Thickener (locust bean gum)
Convenience	Mix into feed, pre-measured sachets	Requires measuring and mixing, adjusting thickness
Flexibility	Fixed dose per sachet	Adjustable — can fine-tune thickness
Bottle flow	Moderate thickening	Can make feed very thick — may need larger nipple
Constipation risk	Higher (contains aluminum)	Lower
Cost	Higher (branded pharmaceutical)	Lower (bulk powder)
Availability	Pharmacy, sometimes prescription	Pharmacy or online
Evidence strength	Weak (Del Buono 2005, n=20)	Weak (small studies, visible symptoms only)

The Bottom Line

Gaviscon Infant and feed thickeners are roughly equivalent for reducing visible reflux symptoms. Neither has strong evidence for superiority. Neither addresses acid production.

If you’re already using a thickener and it’s working reasonably well, switching to Gaviscon is a lateral move, not an upgrade. If you’re not using either and want to try something, pick whichever is more practical for your situation.

If your baby has silent reflux — where the main issue is acid irritation without visible spit-up — neither option directly targets the problem. The real escalation for silent reflux is acid suppression (omeprazole/lansoprazole) via your pediatrician.

When to Escalate

Consider talking to your pediatrician about acid suppression medication if:

Thickeners/Gaviscon haven’t helped after 2 weeks of consistent use
Baby shows signs of feed aversion (pulling off bottle, decreasing intake, pre-feed fussiness)
Weight gain is faltering
Baby seems in significant distress during or after feeds
Sleep is severely disrupted despite positioning and thickening measures

Don’t wait for a magic threshold. If your gut says something isn’t right, that’s enough to ask.

References

Del Buono R, et al. Gaviscon vs Carobel in gastro-oesophageal reflux. Arch Dis Child. 2005;90(5):460-3. PMC1720405.
Buts JP, et al. Role of sodium alginate in treatment of GER in infants. Acta Paediatr Scand. 1987;76(5):820-4. PMID 3032640.
Vandenplas Y, et al. Pediatric Gastroesophageal Reflux Clinical Practice Guidelines. J Pediatr Gastroenterol Nutr. 2009;49(4):498-547.
NICE Clinical Guideline NG1. Gastro-oesophageal reflux disease in children and young people. 2015 (updated 2019).