So Milo can do magical things like perk you up, give you an instant mood boost, and the urge to take a shit immediately after drinking it. WHY?
Cocoa
The chocolaty taste in Milo? Cocoa. Cocoa is a great source of magnesium, which helps to relax the muscles in our digestive tract, increasing the likelihood that you'll need to poop.
Fibre
Though Milo taste like a cocoa drink, it is mostly malt - made out of grains. Guess what? Grains such as brown rice and oats (which are btw, the two main ingredients for making milo) contains high amount of fibre, and aids in digestion. Fiber can help lower your cholesterol and blood sugar levels, but it primary regulates your bowel movements. (Hello toilet trips!)
Gluten
Other than fibre, malt is also known to contain Gluten, which some people are hypersensitive to. However, it seems that Nestlé may have found a way around to not include gluten in the making of Milo as it is not declared on their package. Instead, they neatly sums up their allergens with "Contains milk and soya." Nonetheless, similar to milk, gluten is an allergen and could contribute to abdominal bloating.
Milk
So you thought you drink milo with milk, but turns out, milo itself has milk content! So if you experience some mid-morning cramping after drinking milo, you could be lactose intolerant. That means your small intestine has difficulty digesting and breaking down lactose, which is present in all dairy products. When this happens, the undigested lactose moves into the large intestine, and you know the rest. Although the symptoms can range from mild to severe, for most people the condition isn’t serious, just... unpleasant.
Lastly, if you experience some bowel movements after a good morning Milo drink, don't worry -- it's mostly because you have a healthy digestive system!
All I can say is... yes, you're not alone. And sure, milo's great, but risk running late for work! ;)