Re: Sudden intolerance to lactose in breastmilk?
It would be very unusual for such a young child to suddenly develop true lactose intolerance. Because babies and young children are designed to consume breastmilk, they are also designed to digest lactose. The production of lactase, the enzyme that breaks down lactose, peaks in infancy and early childhood. People who become lactose intolerant typically do so later in life, usually in adolescence or adulthood.
Now, what could be happening- and what seems much more likely to me- is something called "secondary" lactose intolerance, which often follows a gastrointestinal illness. The illness results in a temporary decrease in the production of lactase, and therefore in a temporary difficulty with the digestion of lactose. As the gut heals from the gastrointestinal illness, the production of lactase will rebound and the person will be able to digest lactose again. Now, if this is the problem, then it's not like your milk is "poisoning" your child. It MIGHT give her some increased gastrointestinal distress (diarrhea, flatulence, tummy rumbling, bloating, abdominal discomfort, maybe even nausea and/or vomitting), but it's very unlikely to result in weight loss.
So, let's talk about the diarrhea- how long has it lasted? Is baby getting dehydrated? Is it happening every single day? Is there any sign of improvement? What is baby eating, in terms of solids, at this point? Are you pushing the BRAT diet (bananas, rice, apples, toast) and avoiding the "P" fruits (prunes, plums, aPricots, peaches, pears)? Are you giving baby a daily probiotic? Is baby actually losing weight, and if so, how much?
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