Which of the following would be considered a minor adverse effect of medication?

In considering what constitutes a minor adverse effect of medication, diarrhea is often regarded in that category. While diarrhea can be uncomfortable and inconvenient, it is frequently not life-threatening or severely debilitating compared to more serious side effects.

Nausea is also a common side effect and can significantly impact a patient's quality of life, but it often resolves quickly and typically does not result in serious consequences. Rash, although it can vary in severity, can potentially indicate an allergic reaction or a more serious condition, making it a concern that warrants monitoring. On the other hand, chest pain is generally considered a serious adverse effect as it may suggest underlying cardiovascular issues that require immediate medical attention.

Thus, diarrhea, while unpleasant, is less concerning in the realm of adverse effects when compared to nausea, rash, and especially chest pain.