He is losing weight; his gastrointestinal issues got a lot worse; his gastrointestinal issues got a lot worse; He got salmonella and C-diff after that; He got salmonella and C-diff after that; diarrhea; almost like the stomach flu; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP) from medical information team. The reporter is the patient.  A 61-year-old male patient received bnt162b2 (BNT162B2), on 20May2021 as dose 2, single (Lot number: EW0175) at the age of 61 years intramuscular, in left arm for covid-19 immunisation. The patient's relevant medical history included: "gastrointestinal problems" (ongoing), notes: He has had gastrointestinal problems for 35 years. The patient's concomitant medications were not reported. Vaccination history included: bnt162b2 (DOSE 1, SINGLE, Batch/lot number: EW0187, Anatomical location: left arm near the shoulder. , Route of Administration: intramuscular), administration date: 29Apr2021, for COVID-19 immunisation. The following information was reported: SALMONELLOSIS (medically significant) with onset 2021, outcome "not recovered", CLOSTRIDIUM DIFFICILE INFECTION (medically significant) with onset 2021, outcome "recovered" and all described as "He got salmonella and C-diff after that"; GASTROENTERITIS VIRAL (medically significant) with onset 2021, outcome "unknown", described as "almost like the stomach flu"; DIARRHOEA (medically significant) with onset 2021, outcome "recovering", described as "diarrhea"; GASTROINTESTINAL DISORDER (medically significant), CONDITION AGGRAVATED (medically significant) all with onset Jun2021, outcome "not recovered" and all described as "his gastrointestinal issues got a lot worse"; WEIGHT DECREASED (medically significant), outcome "unknown", described as "He is losing weight". The events "his gastrointestinal issues got a lot worse", "he got salmonella and c-diff after that", "diarrhea", "almost like the stomach flu" and "he is losing weight" required physician office visit. The patient underwent the following laboratory tests and procedures: Clostridium test: (2021) Positive; Occult blood: (unspecified date) Unknown results; (2021) Negative; Parasitic test: (unspecified date) Unknown results; (2021) Negative, notes: believes it was negative; Salmonella test: (2021) Positive; Stool analysis: (2020) Negative; (2023) Negative; Weight: (unspecified date) losing weight, notes: He is losing weight and does not know what his current weight is; Weight: (unspecified date) 165-170 lbs. Therapeutic measures were taken as a result of gastrointestinal disorder, condition aggravated, salmonellosis, clostridium difficile infection, diarrhoea, gastroenteritis viral. Clinical course: Patient was asking for any treatment recommendations of diarrhea due to the Pfizer COVID-19 vaccine. Any recommendation to took a probiotic because he heard that Pfizer COVID-19 vaccine can disrupt the gut bacteria. Any physician or researcher can refer him to provide recommendations for treatment of his diarrhea. May be someone at PRIVACY. Patient reported 35 year history of gastrointestinal problems that worsened after receiving a second shot of the Pfizer covid-19 vaccine. He was having diarrhea, almost like the stomach flu, over the last two years and does not had the diarrhea every day, that it does remit at times. He had Gastrointestinal problems, it got a lot worse after a week or two when he took the second dose of the Pfizer COVID-19 vaccine, he had been a lot worse problems for two and a half years now. He would like to know what advice can we given to him. He had gastrointestinal problems they have been more or less manageable. He took 2 covid vaccines in 2021 and week or 2 after the second dose, his gastrointestinal issues got a lot worse. He got salmonella and C-diff after that. They were both mild cases and took antibiotics to deal with him. He had diarrhea for the last 2.5 years with remissions at times. It was his understanding that the vaccines can disrupt the gut bacteria. He was looking for information was there any type of recommendations for treatment or probiotics. He was losing weight and does not know what his current weight was. Reporter also wanted to include his gastroenterologist in the report. His gastrointestinal issues started getting worse in the early part of Jun2021. Salmonella: Diagnosed with salmonella a couple of weeks after his gastrointestinal issues started getting worse in about Jun2021 or Jul2021. He took cipro and it did not knock it out and so he was given Bactrim to get rid of it. Stated that the cipro took care of it as long as he was taking it, but it came back when he stopped taking the Cipro. C-Diff: Diagnosed with C-Diff around a month after he had salmonella and was treated with antibiotics for salmonella. He was treated for C-diff with Metronidazole. C-Diff came back a few months later in Feb2022. It was not diagnosed the second time because there was a ice storm and he could not get to the doctor office. The doctor said it was probably. C-diff and prescribed metronidazole and it got rid it. He had now was more intermittent, clarified the diarrhea was more intermittent. He was taking minced garlic and was taking a probiotic and that had helped some. The severity of what he was going on now was much worse and had the severity of like a stomach flu. Occult blood test and parasitic test was done more than once. During vaccination patient Could feel cold stuff go into his arm as he expected. Had a family Medical History: Colon cancer- grandmothers on both sides and Father had some colon problems, but was not cancer.; Sender's Comments: Linked Report(s) : US-PFIZER INC-202300366343 Same patient, different drug/AE;