Adverse reaction reports describe suspected side effects. A report does not mean the drug caused the event — co-medications, underlying disease and coincidence all contribute.
Is Colloidal bismuth pectin approved in United States?
Yes. FDA has authorised it.
Who is the marketing authorisation holder for Colloidal bismuth pectin in United States?
Second Affiliated Hospital, School of Medicine, Zhejiang University is the originator. The local marketing authorisation holder may differ — check the official source linked above.