What Leads To Bowel Blockage After Taking Aspirin?

My husband took white bark supplement (two) and he ended up with small bowel blockage and is in the hospital. I did not think he was allergic to aspirin. He is on meds for seizures which could interact. Where is a good source to look up the dangers of supplement by name. I wonder if aspirin is hard on kidneys and liver as white bark apparently is.