Depressed/depression; It has caused diarrhea that has persisted for 8 weeks; Soreness/her shoulder was sore; This is spontaneous report received from a contactable consumer (patient sister, Caregiver). This is report 1 of 2. This report is in regard to the reporter's sister. A 79-year-old female patient received bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE, Solution for injection, Lot Number: Unknown, NDC number: Unknown, Expiry Date: Unknown), via unspecified route of administration on an unspecified date (about two months ago) as 2nd dose single for covid-19 immunization. The patient had History with Oral lichen planus From an Unspecified date and unknown if ongoing). Concomitant medications were not reported. Patient did not have any other product. Reporter stated that, she doesn't know the specific day of vaccination. It has caused diarrhea to the patient that has persisted for 8 weeks. GI doc gave Lomotil, and it helped a little bit. She has had to change her diet and cut out vegetables because it made the diarrhea worse. Patient was very depressed. Patient wanted to know if It was reported earlier and why would it cause the ongoing diarrhea. Patient had seen that that it causes sometimes severe diarrhea, but it didn't say how long it will last. Patient was concerning about if someone need to take an immunosuppressive medication to stop the diarrhea. She was afraid her doctor is going to tell her she needs to take an immunosuppressant medication. It also had stated like, if the Pfizer aware that people have to take medications that shut down the immune system. Upon follow up on 27May2021, reporter stated that, patient was very depressed (on unspecified date) about it. She had a tendency of having autoimmune problems, that she had oral lichen planus, sometimes called burning mouth syndrome. Her doctor diagnosed her with oral lichen planus, which is an autoimmune reaction to bell peppers, she was eating a lot of bell peppers. patient has a hyper immune system. She did not take any type of autoimmune medications no Humira or immunosuppressive medications. Patient took the COVID-19 vaccine 8 weeks ago and patient developed the diarrhea by the 4th day after the vaccine. Patient had never had diarrhea her entire life. Patient went into shock. Her sister's diarrhea was still ongoing. The gastro doctor gave her sister Lomotil and the Lomotil was working to a point, it prevents the worst of the diarrhea. Her stool was coming out very loose. Reporter did not have the NDC number, lot number and expiry date for the Lomotil, stating it was a prescription, chemical name called atropine or something (as reporter). Patient changed her diet and was becoming depressed. Normally, her sister is a person very concerned for her health and she would have a plant-based diet with multiple vegetables, and now her sister can't do that. patient felt her life depends on having a healthy diet. Patient had vaccinated at pharmacy or something, reporter was concerned that, patient got a good vaccination that was not corrupt in any way. Reporter was urging patient to get the vaccine because she travels and goes to a different country and this and that. So, she could be able to travel. patient has a hyperactive immune system, it appears so anyway. Reporter was using her own words when she uses the term hyperactive immune system, so this may not be medically accurate. Her sister has oral lichen planus which is a bad problem. patient was eating a lot of bell peppers. Bell peppers produce an immune reaction, because they contain a chemical called solanine. patient was eating a lot of bell peppers because the internet said they were healthy and contained a lot of vitamin A. she got an immune reaction to the bell peppers, and the immune reaction produced sores under her sister's tongue, very painful sores. Patient had side effects happen three or four days later after the vaccine- it started as diarrhea and she thought it would stop. Patient's shoulder was sore. reporter mentioned she doesn't know when patient's soreness began and ended. The soreness did completely go away for patient. No Additional Vaccines Administered on Same Date of the Pfizer Suspect. Event Did not require any visit to emergency Room or Physician Office. Prior Vaccinations within 4 weeks of the suspect vaccine and events following prior vaccinations were none. Patient's Family Medical History was related to the autoimmune stuff, clarified as the oral lichen planus. Patient had oral lichen planus and was previously treated with steroids. The oral lichen planus started with sores under her sister's tongue. Her sister was treated twice with steroids. Patient said the steroids were successful. Patient's sores were treated with a steroid once and then the sore returned so she went back to the same doctor, and the doctor treated her again with steroids. The second time, the sores went away. At that point, this condition was called burning mouth syndrome, which is on the internet, it was a known condition that is very painful. The doctor diagnosed it as burning mouth syndrome. The diarrhea her sister is experiencing was causing a psychological effect. Reporter stated that, there was no warnings of if a person who has an overactive immune system shouldn't take the COVID vaccine, there was no kind of warning. Reporter seriousness for all the events were Unspecified. Outcome of all the events were unknown.  Information on the lot/batch number has been requested.