Side effects include stomach cramping and diarrhea.
You should not use cascara sagrada when you have stomach pain, nausea, or vomiting. This is true for all laxatives. Do not use cascara if you have chronic intestinal problems. These include Crohn's disease, ulcerative colitis, sprue, appendicitis, stomach ulcers, any unexplained stomach pain, or irritable bowel syndrome.
If you are pregnant or breastfeeding, you should not use cascara sagrada. Your nursing infant may experience diarrhea. This could be caused by cascara sagrada crossing over to the breast milk.
Don't take a higher than recommended dose. There are reports of liver toxicity when taken long-term in higher than recommended doses or for more than 6 days in a row.
Cascara sagrada is not safe for children. They are likely to suffer serious side effects. This includes decreased potassium levels and dehydration.