A bloated stomach after a protein shake does not automatically mean you cannot digest protein. Look at the whole drink: the powder, liquid, serving size, extras and how quickly you drink it.

Whey and the milk used to mix it may both contribute lactose. Low-lactose is not the same as milk-protein-free. Allergy symptoms such as swelling or breathing trouble need urgent care, not a different whey experiment.

If symptoms are mild and familiar, change one thing at a time. Comparing milk with water while keeping the powder and portion the same is more informative than replacing the entire recipe overnight.

Added fibre, some sweeteners, a very large serving and fast drinking may all matter. That does not make every ingredient a problem. Record what you use before creating a long list of foods to avoid.

You do not have to force a shake into your day. Familiar foods can provide protein too. Choose a powder only when it fills a practical gap and you can use it comfortably.

Persistent symptoms, severe pain, blood in the stool or unexplained weight loss need assessment. Bring the product label and a short symptom record. The goal is a comfortable routine, not endless switching between tubs.