Anti-Reflux and Thickened Formula

What the product is

Anti-reflux formula, sometimes sold as staydown formula, is infant formula that has been thickened so the feed is less likely to travel back up the oesophagus. NICE names the usual thickening agents in its guideline on reflux in children: rice starch, cornstarch, locust bean gum or carob bean gum. Separately, some products are sold as a thickening powder to be added to a standard formula rather than as a pre-thickened milk. The NHS mentions both routes.

This page is about the products and the feeding technique around them. It is not an explanation of what reflux is, how common it is, or how it resolves; that belongs elsewhere, and repeating it here would not help you decide whether to buy a tin.

The order NICE puts things in

The single most useful thing to know is that thickened formula is not step one. NICE guideline NG1 sets out a stepped-care approach for formula-fed infants with frequent regurgitation associated with marked distress, and it runs in this order:

• review the feeding history, then
• reduce the feed volumes only if they are excessive for the infant's weight, then
• offer a trial of smaller, more frequent feeds while maintaining an appropriate total daily amount of milk, unless the feeds are already small and frequent, then
• offer a trial of thickened formula.

Three things have to be tried and found wanting before the fourth is reached. NICE's Clinical Knowledge Summary frames the trial length as one to two weeks for thickened formula, the same as for the reduced-volume trial.

The step after that is also specified. If the stepped-care approach does not work, NICE says to stop the thickened formula and offer alginate therapy for a trial of one to two weeks instead. Thickened formula is not something you stay on indefinitely because it did not obviously make things worse.

Why the NHS asks you not to self-prescribe

Anti-reflux formula is available in pharmacies and supermarkets without any gatekeeping. The NHS still recommends that you "only use it on the advice of a health professional". There are two reasons, and the second is a genuine safety issue rather than a bureaucratic one.

The first is diagnostic. NICE points out that cows' milk allergy can present with reflux-like symptoms, and its GORD summary includes considering a trial of management for possible cows' milk allergy where clinically appropriate. The NHS says a doctor may want to check for cows' milk allergy first, "because the symptoms can be very similar to reflux". Thickening the milk does nothing for an allergy and delays the answer.

The second is preparation temperature, below.

The preparation problem

This is the detail that most people never hear. Standard UK guidance for making up powdered formula is water of at least 70C, achieved by boiling and cooling for no more than 30 minutes, because the powder is not sterile and that temperature kills bacteria in it.

Thickened formulas behave differently in hot water. As the NHS explains, "some manufacturers of anti-reflux formula recommend making it up at lower temperatures than are usually recommended. Otherwise it may get lumpy." Follow the pack, but understand the trade-off you are making: the NHS states directly that "it's important to take extra care when making up and storing these products as powdered formula is not sterile and making it up at lower temperatures will not kill any harmful bacteria it may contain".

That is the sharpest practical argument for involving a health professional. A product that comes with instructions to abandon the main food-safety control in infant feeding deserves a reason for being used.

What to try with technique first

The first NICE step is a review of the feeding history, and a good deal of what that review finds is fixable without changing product.

NHS Best Start in Life and the HSE both point at the same handful of things. Hold your baby upright during the feed and keep them upright for as long as you can afterwards. Burp regularly during feeds rather than only at the end. Check the teat: the NHS notes that a hole that is too big lets milk flow too fast, which can make a baby sick, and paced feeding with the bottle almost horizontal slows the whole feed down. Do not force a baby to take more than they want, because the NHS links that specifically to distress and overfeeding. Smaller, more frequent feeds are the third NICE step and can be tried while you are still on ordinary first infant formula.

The thing you must not do

Do not raise the head of the cot or Moses basket, and do not use any sleep positioner or wedge. NICE NG1 states it as a recommendation: "do not use positional management to treat GOR in sleeping infants", and in line with NHS advice on sudden infant death syndrome, infants should be placed on their back when sleeping. A baby with reflux still sleeps flat on their back. This is not a small point; positioning devices sold for reflux run directly against safer-sleep guidance.

Also, do not add cereal or rice to a bottle as a home-made thickener. The AAP has a standing warning against solid food shortcuts in bottles, and it is not the same intervention as a manufactured, nutritionally balanced thickened formula.

Where medicines sit

NICE is explicit that acid-suppressing drugs such as proton pump inhibitors and H2 receptor antagonists should not be offered to treat overt regurgitation occurring as an isolated symptom. A four-week trial is something a clinician may consider where regurgitation comes with unexplained feeding difficulties, distressed behaviour or faltering growth. That decision is not one a parent can make from a shelf, and it sits after the feeding steps, not instead of them.

When to get medical advice

See a GP if things are not improving after trying feeding changes, if reflux appears for the first time after six months, if it is still happening after a year, or if your baby is not gaining weight or is losing weight. NICE lists onset after six months or persistence beyond one year as triggers for paediatric referral.

Seek urgent advice or call 111 for green or yellow vomit, blood in vomit or stool, projectile vomiting, a swollen or tender tummy, a very high temperature, persistent vomiting with no fluids kept down, refusal to feed, or a baby who will not stop crying and is very distressed. NICE also flags progressively worsening or forceful vomiting in infants under two months as needing same-day specialist assessment.