Yes, you may have done some damage, only a professional can tell you for sure. You may want to contact poison control, or see a doctor.
It sounds like it though, with the constipation and bloody stool. I would speak with a doc. ASAP. You may need to go on a special diet while the bowl is healing. Just to give you some idea, if you drank the amount of H2O2 (Hydrogen-Peroxid) you used, you would have needed emergency attention. The bowl is a soft tissue and may need special care in healing, again I would seek professional medical advise.