Felt like intestines were swollen; extreme abdominal pains/ Different pain than diverticulitis; tenderness in abdomen; tired; chills; elevated temp of 99.9F/fever; This is a spontaneous report received from a contactable reporter(s) (Other HCP). The reporter is the patient.  A 79-year-old female patient (not pregnant) received BNT162b2, BNT162b2 omi ba.4-5 (BNT162B2, BNT162B2 OMI BA.4-5), on 15Nov2022 at 17:00 as dose 5 (booster), single (Lot number: 755342) at the age of 79 years, in left arm for covid-19 immunisation. The patient's relevant medical history included: "HPT" (unspecified if ongoing); "diverticulosis" (unspecified if ongoing); "diverticulitis" (unspecified if ongoing); "osteoarthritis" (unspecified if ongoing); "Covid-19" (unspecified if ongoing), notes: if covid prior vaccination: Yes. The patient took concomitant medications. Past drug history included: Alendronate, reaction(s): "known allergies: alendronate". Vaccination history included: BNT162b2 (DOSE 1, SINGLE; Lot Number: EH9899; Anatomical Location: Arm Left), administration date: 04Jan2021, when the patient was 77-year-old, for Covid-19 immunization; BNT162b2 (DOSE 2, SINGLE; Lot Number: E79262; Anatomical Location: Arm Left), administration date: 25Jan2021, when the patient was 77-year-old, for Covid-19 immunization; BNT162b2 (DOSE 3 (BOOSTER), SINGLE; Lot Number: 772588; Anatomical Location: Arm Left), administration date: 29Sep2021, when the patient was 78-year-old, for Covid-19 immunization; BNT162b2 (DOSE 4 (BOOSTER), SINGLE; Lot Number: fj4981; Anatomical Location: Arm Left), administration date: 14Apr2022, when the patient was 79-year-old, for Covid-19 immunization. The following information was reported: GASTROINTESTINAL OEDEMA (medically significant) with onset 16Nov2022 at 05:00, outcome "recovered" (Nov2022), described as "Felt like intestines were swollen"; CHILLS (non-serious) with onset 16Nov2022 at 05:00, outcome "recovered" (Nov2022); PYREXIA (non-serious) with onset 16Nov2022 at 05:00, outcome "recovered" (16Nov2022 at 13:00), described as "elevated temp of 99.9F/fever"; ABDOMINAL PAIN (non-serious) with onset 16Nov2022 at 05:00, outcome "recovered" (19Nov2022 at 05:00), described as "extreme abdominal pains/ Different pain than diverticulitis"; ABDOMINAL TENDERNESS (non-serious) with onset 16Nov2022 at 05:00, outcome "recovered" (Nov2022), described as "tenderness in abdomen"; FATIGUE (non-serious) with onset 16Nov2022 at 05:00, outcome "recovered" (Nov2022), described as "tired". The patient underwent the following laboratory tests and procedures: Body temperature: (16Nov2022) 99.9 Fahrenheit, notes: at 5 am. Therapeutic measures were not taken as a result of gastrointestinal oedema, abdominal pain, abdominal tenderness, fatigue, chills, pyrexia.; Sender's Comments: As there is limited information available, the causal association between the event Gastrointestinal oedema and suspect drug BNT162b2, BNT162b2 omi ba.4-5  cannot be completely excluded.  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 RAs, Ethics Committees, and Investigators, as appropriate.