In my experience, dairy is the number one thing that people should avoid during their recovery from traveller’s diarrhoea (or infection of any form relating to the gut).
Taking dairy often results in persistent diarrhoea because the enzyme breaking down lactose (the sugar found in dairy) exists on the most superficial layer of the gut wall lining. During infection and inflammation, this superficial layer is often sheared off, resulting in the inability to absorb the lactose, causing watery stools, despite having the initial infection cleared out of one’s system. So DO avoid that milk or ANY products that may have dairy in it.
Also avoid excessively oily or spicy food and drinking any alcohol, as these can cause inflammation and are hard to digest for an inflamed gut.
Avoid anything that is partially cooked (i.e. Half boiled egg, rare steak) as these can contain harmful bacteria that cause more infection in your gut.
So, What should I eat?
You may have heard of BRAT - Banana, rice, applesauce and Toast - if you grew up in the western world.
However, you’ve probably never heard of this if you grew up in Singapore- who really eats applesauce here?
Start slow. Try hydrating fluids like electrolyte drinks, or clear feeds like broth-based soups. If tolerated, then porridge or congee should be next as they have a high water content and the simple carbohydrate to turn into easily energy to fight off your infection and repair your body.