India, Aug. 2 -- I have a 2-month-old baby who is exclusively breastfed. In the last week, I have noticed that motions are a bit loose and have blood streaks. I have been told my baby might have cow's milk protein allergy. I have read about lactose intolerance. I am very confused and distressed. What does my baby have, and what is the treatment? First of all, I'd like to congratulate you on the arrival of your baby and would like to applaud you for exclusive breastfeeding. Breast milk is the best gift a mother can give her baby, designed to meet the nutritional needs of the baby in terms of proteins, fats, and carbohydrates. It is available on demand and at the right temperature, and offers numerous benefits long term to both, baby and mother. Coming to what your baby has, the most likely diagnosis is cow's milk protein allergy (CMPA). We are increasingly seeing this condition in babies. CMPA used to be rare, but not anymore. You might be wondering how this diagnosis can be entertained when you have not given cow's milk to your baby. Your baby has been exposed to cow's milk protein, which has been passed on in breast milk. Minuscule amounts of these are enough to trigger an allergic response in a baby. CMPA can present with blood in stools, as in your baby's case, or there might be other gastrointestinal manifestations like vomiting, diarrhoea, colic, irritability, or failure to put on weight. The diagnosis of CMPA is usually made clinically and does not require any tests (blood or stool) or endoscopic examinations. The treatment is based on removing exposure to the offending allergen. Once you stop ingesting cow's milk or products containing it, the exposure will stop and the healing will start, which can take several weeks. During this process, blood may be visible from time to time and should not cause you worry. It is hard to predict how long CMPA will persist in your baby, but the good news is that it is not permanent. By the ageof 1, the majority of babies can tolerate cow's milk, though some children may develop symptoms up to 5 years. There is a protocol to be followed in terms of reintroducing cow's milk and it considers several factors. Make the plan after consulting with your expert. To answer your question about lactose intolerance, it is important to understand the difference between lactose intolerance and CMPA. Lactose intolerance manifests with flatulence, tummy discomfort, and is related to the ability of an individual to break down lactose - the sugar in milk. Primary lactose intolerance is very rare. We usually see secondary lactose intolerance, which develops after an episode of diarrhoea, as lactase - the enzyme present in the lining of the intestine - gets diminished due to an infection. In a matter of days, this enzyme starts to get replenished and lactose intolerance ceases to be a problem. Lactose intolerance is not an allergy but related to the ability of the intestine to handle the processing of lactose. When the threshold is exceeded, ie the load of lactose is more than a critical level, intolerance develops. Treatment resolves around reducing the lactose and not stopping cow's milk. The author is a leading pediatric gastroentologist and hepatologistwith over three decades of experience and five books to his credit, includingIs Your Child Ready to Face the World?...