Yes, excessive consumption of protein powder can cause diarrhea in some individuals. This is because large amounts of protein can be difficult for the body to digest, leading to an increase in stool volume and frequency. Additionally, some individuals may be sensitive to certain ingredients in protein powder, such as lactose in whey protein or artificial sweeteners, which can also cause digestive symptoms such as diarrhea.

To avoid diarrhea, it is important to follow recommended serving sizes and not to exceed the recommended daily intake of protein. If you experience digestive symptoms after consuming protein powder, it's best to reduce your intake or switch to a different type of protein powder that is better tolerated. Additionally, increasing your fluid intake and consuming adequate fiber can help to reduce the risk of diarrhea.