Lactose intolerance in babies

Infants with lactose intolerance commonly present with one or more of the following symptoms: loose, watery stools; abdominal bloating; pain; increased flatus; and nappy rash.

Lactose intolerance is most common following an episode of infectious gastroenteritis when damage to the bowel lining results in a deficiency in lactase – the enzyme which breaks down the lactose in milk. This causes temporary lactose intolerance (known as secondary lactose intolerance) that usually lasts between 6 and 8 weeks.

Therefore, if a baby has gastroenteritis, and passes uncommonly loose stools for more than 2 weeks, it could be a sign of lactose intolerance. If the diarrhoea resolves within 2 weeks of excluding lactose from the diet, this would confirm a diagnosis of lactose intolerance.1 Secondary lactose intolerance may also develop in some children with gut-related symptoms associated with non-IgE-mediated cows’ milk protein allergy, which resolves following exclusion of cows’ milk protein.

Depending on the cause, lactose intolerance may be temporary or permanent.

Primary lactose intolerance

  • This is the most common cause of lactose intolerance worldwide with prevalence related to ethnicity21

Secondary lactose intolerance

  • A common but temporary cause of diarrhoea. It often occurs because of damage to the intestinal brush border – the site of lactase production

Congenital lactose intolerance

  • A rare condition where newborn babies produce very little or no lactase as a result of an inherited genetic fault that runs in families

Developmental lactose intolerance

  • Some preterm babies (born before the 37th week) experience temporary lactose intolerance due to immaturity of the small intestine. This usually improves as affected babies get older and their gut fully develops

Advice for parents

  • If a mum is lactose intolerant, it is completely safe for her to breastfeed her baby21
  • Breastfed babies may benefit from lactase substitute drops
  • Lactose-free formula milks are available for formula-fed babies or lactase drops can be added to baby’s usual formula feed
  • For many babies, lactose intolerance is temporary and will improve after a few weeks

Further information and support

National Health Service (NHS) Nottinghamshire Area Prescribing Committee. Guidance on the management of lactose intolerance and cows’ milk protein allergy and the prescription of specialised infant formula. 2011
National Institute of Health and Care Excellence (NICE). Clinical guidance 116: Food allergy in children and young people: Diagnosis and assessment of food allergy in children and young people in primary care and community settings. 2011 

For parents

NHS Choices - Lactose intolerance. 2014
Great Ormond Street Hospital. Lactose intolerance information. 2014 

Benefits of lactose-free formula

Studies have shown that some infants with acute diarrhoea who are fed lactose-free formula have a faster resolution of their symptoms than infants fed a formula containing lactose.22,23

Infants fed lactose-free formula show comparable growth and absorption of key nutrients. When tested, there were no significant differences for the absorption of magnesium, phosphorus, calcium and nitrogen content.24

  1. Department of Health. Infant feeding recommendation. May 2003 Available here.
  2. Best Practice for Infant Feeding in Ireland. Food Safety Authority of Ireland, 2012.
  3. Iacono G et al. Dig Liver Dis 2005; 37: 432–438.
  4. National Institute for Health and Care Excellence (NICE). Clinical Knowledge Summary (CKS): Constipation in children. September 2010. Available here.
  5. National Institute for Health and Care Excellence (NICE). Clinical Guideline. Constipation in children and young people: Diagnosis and management of idiopathic childhood constipation in primary and secondary care (CG99). May 2010.
  6. Tabbers MM et al. JPGN 2014; 58: 258–274.
  7. NHS Choices. Colic. 2014. Available here.
  8. National Institute for Health and Care Excellence (NICE). Clinical Knowledge Summary (CKS): Colic - infantile. November 2014. Available here.
  9. Vandenplas Y et al. Nutrition 2013; 29: 184–194.
  10. Billeaud C et al. Eur J Clin Nutr 1990; 44: 577–583.
  11. Infante D et al. World J Gastroenterol 2011; 17: 2104–2108.
  12. Carnielli VP et al. J Pediatr Gastroenterol Nutr 1996; 23: 553–560.
  13. Yao M et al. JPGN 2014; 59: 440–448.
  14. Limanovitz I et al. The effects of infant formula beta-palmitate structural position on bone speed of sound, anthropometrics and infantile colic: a double blind, randomized control trial. ESPGHAN 2011.
  15. Hyman PE et al. Gastroenterology 2006; 130: 1519–1526.
  16. Ramirez-Mayans J. J Int Pediatr 2003; 18: 78–83.
  17. Vandenplas Y et al. J Pediatr Gastroenterol Nutr 2009; 49: 498–547.
  18. National Institute for Health and Care Excellence (NICE). Clinical Knowledge Summary: GORD in children. March 2015. Available here.
  19. Moukarzel A et al. J Clin Gastroenterol 2007; 41: 823–829.
  20. Xinias I et al. Curr Ther Res Clin Exp 2003; 64: 270–278.
  21. Heyman MB, Committee on Nutrition. Pediatrics 2006; 118: 1279–1286.
  22. Saneian H et al. Iran J Pediatr 2012; 22: 82–86.
  23. Huang Y, Xu JH. Chin J Contemp Pediatr 2009; 11: 532–536.
  24. Moya M et al. Acta Paediatr 1999; 88: 1211–1215.

*Ingredients of all formulas were confirmed by telephoning company carelines dedicated to answering queries about their products (March 2015). 

IMPORTANT NOTICE: Breast milk is best for babies and breastfeeding should continue for as long as possible. This product must be used under medical supervision. SMA LF is a lactose free milk based formula for the dietary management of babies and young children who are intolerant to lactose or sucrose, or who are suffering from symptoms such as diarrhoea, tummy ache or wind caused by temporary lactose intolerance. It is suitable as the sole source of nutrition up to 6 months of age, and in conjunction with solid food up to 18 months of age. SMA LF is not suitable for those who are allergic to cows’ milk protein, or who suffer from galactosaemia or require a galactose free diet.