a15e0d46_Health_Information_Library__Recommendation
[Why] People whose diarrhea is caused by lactose intolerance can avoid the problem by steering clear of milk and ice cream or by taking lactase, the enzyme needed to digest lactose. People who are lactose intolerant -meaning they lack the enzyme needed to digest milk sugar-often develop diarrhea after consuming milk or ice cream. People whose lactose intolerance is the cause of diarrhea will rid themselves of the problem by avoiding milk and ice cream or in many cases by taking lactase , the enzyme needed to digest lactose. Lactase is available in a variety of forms in pharmacies (and in grocery stores in the form of lactase-treated milk). [Recommendation] 
If you're lactose intolerant, avoid milk products
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