Is it safe to take the cleansing drink omni during pregnancy?
It contains cascara sagrada bark and I want to make sure it won't harm the baby since I'm only taking it once

If you are taking it for constipation issues you would be better off changing your diet instead. Cascara Sagrada is considered a "class c" drug... which means not enough testing has been done to determine if there is a concern, and some testing on animals has shown a possible risk.

Gradually increase your fiber intake, increase fresh fruits and vegetables, and increase your fluid intake. You would be better off with something such as Metamucil (class b drug... testing has been done and not shown a risk, although risks are not totally ruled out) if you were to try something in addition to diet changes.

Always best to check with your care provider before using any sort of medicine or herbal supplement as conditions in your pregnancy may be different from someone else's.