This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP) for a Pfizer sponsored program. The reporter is the patient. A 60 year-old male patient received bnt162b2 (BNT162B2), administered in arm left, administration date 21Mar2021 11:00 (Lot number: CV8732) at the age of 60 years as dose 1, single and administration date 30Apr2021 (Batch/Lot number: unknown) as dose 2, single for Covid-19 immunisation. The patient's relevant medical history and concomitant medications were not reported. The following information was reported: DIARRHOEA (non-serious) with onset 22Mar2021, outcome "unknown", described as "really loose bowel movements/ and multiple bowel movements in the morning, bordering on watery diarrhea by noon"; EATING DISORDER (non-serious), outcome "unknown", described as "He can't eat or drink anything without it generating movement"; WEIGHT DECREASED (non-serious), outcome "unknown", described as "after the diarrhea patient weighed 152lbs and prior to the first dose Pfizer Covid Vaccine caller weighed 165lbs". The events "really loose bowel movements/ and multiple bowel movements in the morning, bordering on watery diarrhea by noon", "he can't eat or drink anything without it generating movement." and "after the diarrhea patient weighed 152lbs and prior to the first dose Pfizer Covid-19 vaccine caller weighed 165lbs" were evaluated at the physician office visit. Relevant laboratory tests and procedures are available in the appropriate section. Additional info: Pretty much within a day of receiving the first vaccine, diarrhoea began within a day or two after the first dose Pfizer Covid-19 Vaccine. He started having really, really loose bowel movements and multiple bowel movements in the morning, bordering on watery diarrhea by noon. Patient clarifies he started seeing some diarrhea with some substance to it, in other words, it wasn't just watery, it was kind of mush. The diarrhea was pretty much in the mornings and by noon it would calm down and he was eating his normal diet, and it didn't wake him at night. Patient's diarrhea continued unabated with no solid stools until caller received the second dose Pfizer Covid 19 Vaccine. Patient received his second dose, the diarrhea has now regressed to almost like urinating out of his back side, it's just complete liquid with little bits and pieces and it's non-stop. He can't eat or drink anything without it generating movement. He clarifies further by the second week of April, the diarrhoea had progressed to pure water. Then the second dose accelerated the diarrhoea. He confirms after the second dose the diarrhoea became around the clock (it didn't stop by 12:00 or 13:00). The diarrhoea has worsened since the second vaccine. The weight loss began most drastically in the last two and a half to three weeks.  Caller didn't see as much weight loss when he first had the shot, but in between the first dose and the second dose, he saw pretty significant weight loss. The weight loss has definitely accelerated since the second dose Pfizer Covid 19 Vaccine. After he had a full dinner last night, he definitely gained back some of weight lost earlier in the day. In between bouts of diarrhea, having a full meal did put weight back on. But then, the next morning or through the night, caller would lose pretty much the weight that he had gained back. Caller would say the weight loss has leveled off. Caller reports no cramping, no bloating, and no fever. Caller feels perfectly fine other than the way the bowel movements look, sound, and splash. No follow-up attempts are possible; information about lot/batch number cannot be obtained. No further information is expected.