Step 4: Read and complete the decision guide to learn more about your symptoms.
It is common for adults to lose their ability to digest the milk sugar lactose. "Lactose intolerance" could be a cause of your diarrhea even if milk digestion used to be normal for you.
About Lactose Intolerance
Undigested lactose passes into your colon where it can nourish bacteria and ferment into gas. Undigested milk products can also cause diarrhea and abdominal cramps.
Lactose intolerance can be managed with total or near-total avoidance of milk and dairy products. Some people improve symptoms by swallowing a milk digestion aid with meals called lactase (Lactaid).
One of the most practical steps in your diarrhea evaluation might be to carefully eliminate milk and milk products for several weeks, to see if your diarrhea improves.