The lactose deficiency causing lactose intolerance
may be primary that is since birth or may be acquired.
The acquired intolerance is following an episode of intestinal infection resulting in gastroenteritis
The most common cause is rotavirus
infection. This infection results in temporary lactose intolerance due to the resulting damage to the superficial intestinal lining of the intestines, the brush border cells, which produce an enzyme called lactase, needed to digest the lactose present in the milk.
The symptoms improve once the cell lining recovers. Did you breast feed your child? If so and if your child was tolerating the breast feeds then primary lactose deficiency is ruled out.
Why were you giving your baby lactose-free milk? Was that after an episode of loose stools?
A routine Stool examination with the presence of reducing substances will help in diagnosis. A breath test
is also available.
However, it may not be possible to do in a small child. It is recommended that you keep your baby off all dietary products containing lactose for a period of 2-4 weeks and then gradually reintroduce them.
Hope I have answered your query. Let me know if I can assist you further.
Dr Anil Kumar Bhatnagar, Pediatrician