Babies are becoming violently ill after drinking a new formula milk touted by manufacturers as ‘brain boosting’, child nutrition experts have warned.

Alarmed mothers have complained that the powdered milk with fish oil makes their babies vomit and some have been taken to hospital with severe reflux.

Fish oils have been added to major brands such as SMA and Aptamil to tempt parents who believe the Omega 3 fatty acids they contain help growing brains.

Agony: Baby Tahlia Arnold, with parents Stephen and Emma, suffered after having milk with fish oil

But experts say babies cannot process fish oil, leading some to vomit the milk back up. Others suffer colic, diarrhoea and constipation.

More than 13,000 parents have signed a petition demanding that Nestlé 'ban SMA Pro Formula Milk' after it changed its ingredients in January.

The three big brands – SMA, Aptamil and Cow & Gate now all include fish oil in their ‘standard’ newborn milks.

Manufacturers admit some infants take time to get used to the new formula. But they insist babies are no more likely to suffer reflux or other digestive problems than if they use formulas without fish oil.

But top child doctor Colin Michie last night said there was ‘very little science’ to claims that fish oil helps brain development in newborns.

Dr Michie, chairman of the nutrition committee at the Royal College of Paediatrics and Child Health, added: ‘If we feed babies cows’ milk with fish oil added, we will come across a problem – because we didn’t develop to have that in our diet as a baby.

'Certainly, there’s an awful lot more prescription medicine being used to treat reflux in babies than ever before.’

The three big brands – SMA, Aptamil and Cow & Gate now all include fish oil in their ‘standard’ newborn milks

Reflux is common in babies and is not usually a major cause of concern. But repeated episodes can cause stomach acid to damage the oesophagus.

Doctors frequently prescribe Gaviscon Infant as a remedy – and they are handing out a third more than they were just five years ago. The medicine cost the NHS in England £5.2 million in 2015, double the £2.6 million of 2010.

Little Tahlia Arnold spent the first months of her life in agony. She cried constantly, her stomach was rock hard and she was badly constipated.

Father Stephen, 26, said: ‘She was in severe pain. She was always tense, her face would be red and she’d be flustered all the time.’ Her breath also smelled acidic.

Stephen and fiancée Emma Owen, 28, both teaching assistants from Caerphilly in South Wales, consulted their GP, who diagnosed colic. But the usual remedies didn’t work.

Emma asked for help on a Facebook page for new mums. Kim Ovenstone, a maternity nurse with three decades of experience, replied.

Stephen said: ‘We told her Tahlia was on Aptamil First Infant Milk 1. Kim told us to try one which didn’t contain fish oils.

'Within a day or two, Tahlia was a different baby. She didn’t cry, there was no high-pitched screaming and she was going to the toilet a lot easier.’

A Nestlé spokesman said: ‘The decision to include DHA [an omega-3 fatty acid] from fish oil in our formulas was only taken following years of clinical testing'

A Nestlé spokesman said: ‘The decision to include DHA [an omega-3 fatty acid] from fish oil in our formulas was only taken following years of clinical testing that showed babies tolerated the formula very well.’

A spokeswoman for Danone, which owns the Aptamil and Cow & Gate brands, said: ‘Infant milks are strictly regulated and all ingredients are tested for their suitability for infants and to ensure healthy growth and development.