bloody diarrhea; felt awful; heavy flu-like symptoms; stomachache; loose stool; weakness; achiness; This is a spontaneous report from a contactable physician (patient). A 65-year-old female patient received the second dose of bnt162b2 (BNT162B2, Solution for injection, lot number: EW0179), dose 2 via an unspecified route of administration, administered in the right deltoid, on 20May2021 10:30  (received at 65-years-old) as 2ND DOSE, SINGLE for COVID-19 immunization. The patient did not receive any other vaccines within the four weeks prior to receiving BNT162B2. The patient stated the only relevant medical history she has is that 10 or 20 years ago she had taken a steroid drug and had gastritis where there was a little blood in her intestinal tract and then when she was pregnant she had a hemorrhoid where there was a little blood, but never really had any other intestinal problems. Concomitant medications were unspecified; the patient stated she has some chronic medical conditions and takes medication for them, but they do not interact with the vaccine and there is nothing that affects her immune system. The patient previously received the rubella vaccine when she was about 25-years-old and had an intense reaction; her knees swelled up like a balloon and she was incapacitated for a week. The patient previously received the first dose of BNT162B2 (BNT162B2, lot number: EW0175), administered in Right arm deltoid muscle on 29Apr2021 at 10:30 for COVID-19 immunization at the age of 65-years-old. The patient experienced bloody diarrhea (diarrhoea haemorrhagic) (medically significant) on an unspecified date, felt awful (malaise) (medically significant) on an unspecified date, weakness (asthenia) (medically significant) on 21May2021, achiness (pain) (medically significant) on 21May2021, heavy flu-like symptoms (influenza like illness) (medically significant) on an unspecified date, stomachache (abdominal pain upper) (non-serious) on an unspecified date, loose stool (diarrhoea) (non-serious) on 24May2021. After the second dose, and it has been 5 days now since getting the second dose, the patient had diarrhea and now is having bloody diarrhea and wants to know if this has been reported. The diarrhea is now bright red blood. The patient stated that yesterday (24May2021), she started with the stomach ache and loose stool or diarrhea. Today (25Ma2021), she had a bout of, moderate amount of, bright red bloody diarrhea. The patient further stated this had improved but now she is losing blood so because of that is has worsened. She stated it was not serious until today and then all of a sudden, she had a moderate bright red amount of diarrhea which she has never had, and it is medically significant. She stated that yesterday she had a lot of diarrhea in terms of volume and the volume has gotten better today but now it is bright red which is concerning. She initially mentioned that about 6 hours after the second dose she started feeling like she had a bad case of the flu and felt really bad for like 3 days and that was letting up. Clarified that starting 21May2021, for the first 2 days after the second dose of the Covid 19 Vaccine: Patient further described as very heavy flu-like symptoms; severe achiness; weakness; just felt awful but events are much better now, now she has light symptoms which are improving. She would say it was medically significant but now it is barely insignificant. The adverse events did not require a visit to the emergency room or physician office. The patient did not receive any corrective treatment for the adverse events. Outcome of the events was recovering.; Sender's Comments: Based on available information, a possible contributory role of the subject product, BNT162B2 vaccine, cannot be excluded for the bloody diarrhea and the other  reported events due to temporal relationship.   There is limited information provided in this report.  Additional information is needed to better assess the case, including complete medical history, diagnostics including stool cultures and colonoscopy, counteractive treatment measures and concomitant medications. This case will be reassessed once additional information is available.  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.