hemoglobin 8.7 g/dL and platelets 60*109/L; bloody diarrhea; This is a literature-spontaneous report. The same author reported different events for 4 patients received Pfizer vaccine. This is the 1st of 4 reports.  The reports describing 19 of 20 patients with thrombocytopenia following vaccination Pfizer and Moderna SARS-CoV-2 vaccination, included age (range 22-73 years old; median 41 years) and gender (11 females and 8 males). Nine received the Pfizer vaccine and 11 received the Moderna vaccine. All 20 patients were hospitalized and most patients presented with petechiae, bruising or mucosal bleeding (gingival, vaginal, epistaxis) with onset of symptoms between 1-23 days (median 5 days) post vaccination. Platelet counts at presentation were available for all 20 cases with the majority being at or below 10*109/L (range 1-36*109/L; median 2*109/L).  This case refers to an 80-year-old male patient with multiple medical problems including recent transcatheter aortic valve replacement, hypothyroidism, and diverticulosis presented 6 days after the Pfizer vaccine with bloody diarrhea, hemoglobin 8.7 g/dL and platelets 60*109/L. He received several units of packed red blood cells and two units of platelets with improvement to 101*109/L and was discharged 5 days later. There were a handful of reports with minimal additional details alluding to a male who passed away in Dec2020 from brain hemorrhage following the Pfizer vaccine-these could be describing the index patient. There were a handful of reports with minimal additional details alluding to a male who passed away in December from brain hemorrhage following the Pfizer vaccine-these could be describing the index patient.  In summary, we cannot exclude the possibility that the Pfizer and Moderna vaccines have the potential to trigger de novo ITP (including clinically undiagnosed cases), albeit very rarely. Distinguishing vaccine-induced ITP from coincidental ITP presenting soon after vaccination is impossible at this time.  No follow up attempts are needed; information about lot/batch number cannot be obtained. No further information is expected.; Sender's Comments: Based on the information currently provided (plausible time association), it cannot be fully excluded that the SARS-CoV-2 vaccination might have played a contributory role in triggering the occurrence of thrombocytopenia complicated by bloody diarrhea leading to blood loss requiring blood products infusion.  The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to Regulatory Authorities, Ethics Committees and Investigators, as appropriate.,Linked Report(s) : US-PFIZER INC-2021353705 same reporter, different patient, same suspect , different event;US-PFIZER INC-2021014534 same reporter, different patient, same suspect , different event;US-PFIZER INC-2021344239 same reporter, different patient, same suspect , different event; Reported Cause(s) of Death: passed away in December from brain hemorrhage