Here's a guide of what's what, and what parents can do:

Constipation

Constipation can be caused by different things such as a lack of fibre in the child's diet or some types of medical conditions and medication. Behaviour such as withholding bowel movements (when children deliberately stop themselves from passing stool), and certain transitions in a child's life such as toilet training and changes in their routine may also to be blamed.¹ Constipation can get worse over time, so parents need to be observant for symptoms like straining while passing stool or clenching buttock muscles. Children may also experience stomach pain or cramping, urinary leakage, or stool in their underwear caused by leaking stool...² Help prevent constipation by giving children two servings of fruits and vegetables and plenty of water daily.³

Diarrhoea

Passing loose, watery stools three or more times in a day means a child is having diarrhoea. The consistency of the stools is the most important sign, rather than the frequency.⁴ Diarrhoea lasting one or two days is usually caused by an infection, while longer-lasting episodes may be caused by a disease or disorder. However, even short episodes can cause dehydration from the loss of fluid and electrolytes (minerals such as calcium, potassium and sodium⁵) in the loose stools. This is why it's important to seek a doctor's advice promptly.⁶

Lactose Intolerance

Lactose intolerance means that the body is unable to digest lactose in milk – this is different from Cow's Milk Protein Allergy (CMPA), which is the body's immune response towards milk protein. Both lactose intolerance and CMPA cause similar symptoms such as nausea, bloating and diarrhoea, so only a trained doctor can make the correct diagnosis and advise parents on the correct way to manage either condition.⁷

A balanced diet with enough fibre and lots of water is important for a child's overall growth and development.³ In addition, keeping the digestive system healthy helps to keep children healthy as well because the system fulfills many important functions ranging from ensuring the proper absorption of nutrients to supporting the immune system.⁸

The digestive system also requires the proper balance of bacteria and microorganisms to stay healthy.⁹ Prebiotics such as galactooligosaccharides (GOS) and fructooligosaccharides (FOS) found in growing up milk formulas can help support digestive health.⁸