Covid booster shot; she is now having diarrhea of the mouth; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non HCP).  A 71-year-old female patient received bnt162b2 (BNT162B2) (Batch/Lot number: unknown) as dose 3 (booster), single for covid-19 immunisation. Relevant medical history included: "cancer" (unspecified if ongoing), notes: had cancer but that was years ago. There were no concomitant medications. Vaccination history included: Bnt162b2 (Dose: 1), for COVID-19 immunization, reaction(s): "sick"; Bnt162b2 (Dose: 2), for COVID-19 immunization, reaction(s): "could not control her bowels, either way", "basically couldn't stand", "still can't sleep on her right side. If she does, it triggers her./Driving for her, is very minimal and she hardly ever drives anymore. She can't drive at night anymore", "motion sickness", "severe vertigo". The following information was reported: IMMUNISATION (non-serious), outcome "unknown", described as "Covid booster shot"; DIARRHOEA (non-serious), outcome "not recovered", described as "she is now having diarrhea of the mouth".  Additional information: The reporter stated that his mom also suffers from vertigo and motion sickness. She had pretty severe vertigo like he did. After his mom's booster, she ended up in the hospital. He states his mom had a similar reaction as he, the caller, did. She ended up in the hospital and she did not even tell him it was because of the shot. He states that his mom did not tell him until a couple of days ago. He states that 3 weeks after she got her shot, his mom had severe vertigo. She could not control her bowels, either way and she basically couldn't stand. She still can't sleep on her right side. If she does, it triggers her. Driving for her, was very minimal and she hardly ever drives anymore. She can't drive at night anymore. He states his mom has been having major issues. He does not know her name but states that his mom did tell him the other day that her doctor told her that exactly 3 weeks after she got her shot, she had the same thing happen. He thinks and was 95 percent sure, his mom said she was going to call Pfizer because she gave him the number to call. He states she will probably be able to give everything about it. Event Details: Clarified that his mom's symptoms started exactly 3 weeks after she got the second Covid shot. He states that she ended up in the hospital. Clarified that she was admitted to the hospital and kept overnight, for one night. The reporter mother had taken the first two doses of the Pfizer Covid vaccine and the Covid booster. He clarified that he thinks she had the booster in Aug2021 or Sep2021 but states that when she had the booster, she had nothing. With her first shot, she felt sick for a day and it was the second one that got her. NDC, LOT, EXP first 2 doses Pfizer Covid-19 vaccine and booster shot: Unknown. Tests: No. She didn't really know much, she went to the hospital and was released. She was real low key about everything until the other day. He states that she is now having diarrhea of the mouth, telling everything about what happened to her. Reporter clarified that when his mom had told him that she went to the doctor, and the doctor had asked her how long it had been since she got that shot, she stated it was 3 weeks. The mom stated that her doctor told her that exactly 3 weeks after her shot, she had vertigo for the first time in her entire life. She stated she was hit with severe vertigo and she had never had it before. Caller states he has no further details to provide about this. NDC number of pfizer covid vaccine was unknown. Expiry date of pfizer Covid vaccine was unknown. No other products. No investigation assessment. Vaccine Lot expire date was unknown. Time the Vaccination was not provided. Anatomical location of administration of pfizer vaccine considered as suspect was unknown. Vaccination facility type was physician Hospital. No any additional vaccines administered on same date of the pfizer suspect.  The lot number for bnt162b2 was not provided and will be requested during follow up.