It is well known that the adverse effects of Metronidazole might ruin an individual's appetite and disturb the stomachs. The unpleasant taste alone can cause nausea and even vomiting in many people. Additionally, indigestion, diarrhea, and constipation might happen. It is enough to cause some people to completely quit their therapy. Always consult the physician in case of any trouble. To assist and prevent an upset stomach, the regular release pills can be taken with a meal, a snack, or a glass of milk.