The role of breastfeeding in reducing morbidity and mortality from gastrointestinal illness in infancy is well established.

Since it is rarely either ethical or possible to conduct randomised controlled trials of infant feeding methods, most studies are either observational cohort studies or case control studies. In 1986 Bauchner et al set out the four important criteria that non-randomised studies needed to meet in relation to their scientific validity and generalisability. (These were that they were prospective, controlled for confounding variables, clearly defined the outcomes and clearly defined “breastfeeding”). Studies published since that time which have met at least three of the four criteria have provided strong evidence of a causal relationship between breastfeeding and gastrointestinal illness. The strength of the relationship may depend on the “amount” of breastfeeding, with exclusive breastfeeding for six months providing the greatest “benefit”.

Good quality studies identified by systematic reviews have formed the basis of several meta-analyses listed below.

Ip S et al (2007) Breastfeeding and Maternal Health Outcomes in Developed Countries. AHRQ Publication No. 07-E007. Rockville, MD: Agency for Healthcare Research and Quality

Ladomenou F, Moschandreas J, Kafatos A, et al. 2010.  Protective effect of exclusive breastfeeding against infections during infancy: a prospective study. Arch. Dis. Child. 27 September 2010, 10.1136/adc.2009.16

Quigley M.A., Kelly Y.J., Sacker A.S. (2007) Breastfeeding and Hospitalization for Diarrheal and Respiratory Infection in the United Kingdom Millennium Cohort Study. Pediatrics; 119; e837- e842

Kramer MS et al (2003) Infant growth and health outcomes associated with 3 compared with 6 mo of exclusive breastfeeding. Am J Clin Nutr 78: 291-295

Wright CM, Parkinson KN and Drewett RF (2004). Why are babies weaned early? Data from a prospective population based cohort study. Archives of Disease in Childhood 89: 813-816

Howie PW et al. (1990). Protective effect of breastfeeding against infection. BMJ 300: 11-16

Bauchner H, Leventhal JM, Shapiro ED.1986. Studies of breast-feeding and infections - How good is the evidence? JAMA. 1986 Aug 15; 256(7):887-92. Review.

Duijts L, Jaddoe VWV, Hofman A et al (2010) Prolonged and Exclusive Breastfeeding Reduces the Risk of Infectious Diseases in Infancy. Pediatrics; 126: e18-e25

Paricio-Talayero JM, Lizán-García M, Otero Puime A, Benlloch Muncharaz MJ, Beseler Soto B, Sánchez-Palomares M, et al. Full breastfeeding and hospitalization as a result of infections in the first year of life. Pediatrics2006;118:e92-9

Klement E, Cohen RV, Boxman J, Joseph A, Reif S. 2004. Breastfeeding and risk of inflammatory bowel disease: a systematic review with meta-analysis.Am J Clin Nutr; 80(5): 1342-52

Pearce MS et al (2005). Does Increased Duration of Exclusive Breastfeeding Protect Against Helicobacter Pylori Infection? The Newcastle Thousand Families Cohort Study at Age 49-51 Years. J Pediatr Gastroenterol Nutr 41: 617-620

Akobeng AK et al (2006). Effect of breast-feeding on risk of coeliac disease: A systematic review and meta-analysis of observational studies. Arch Dis Child 91: 39-43

Rebhan B, Kohlhuber M, Schwegler U, Fromme H, Abou-Dakn, Koletzko BV. Breastfeeding duration and exclusivity associated with infants’ health and growth: data from a prospective cohort study in Bavaria, Germany. Acta Paediatr2009;98:974-80