Microscopic Colitis  2.5 days after 2nd dose; Diarrhea 15 times a day after 2nd dose; she has lost 9 Lbs; This spontaneous case was reported by a physician and describes the occurrence of COLITIS MICROSCOPIC (Microscopic Colitis  2.5 days after 2nd dose) in a 66-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 829L20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.   On 19-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. In February 2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. In February 2021, the patient experienced COLITIS MICROSCOPIC (Microscopic Colitis  2.5 days after 2nd dose) (seriousness criterion medically significant), DIARRHOEA (Diarrhea 15 times a day after 2nd dose) and WEIGHT DECREASED (she has lost 9 Lbs). The patient was treated with BUDESONIDE for Adverse event, at an unspecified dose and frequency and BISMUTH SUBSALICYLATE, CALCIUM CARBONATE (PEPTO BISMOL [BISMUTH SUBSALICYLATE;CALCIUM CARBONATE]) ongoing since an unknown date for Adverse event, at an unspecified dose and frequency. At the time of the report, COLITIS MICROSCOPIC (Microscopic Colitis  2.5 days after 2nd dose), DIARRHOEA (Diarrhea 15 times a day after 2nd dose) and WEIGHT DECREASED (she has lost 9 Lbs) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In February 2021, Colonoscopy: abnormal (abnormal) Patient visited a GI Doctor and was diagnosed with  Microscopic Colitis. In February 2021, Weight: decreased (Low) Lost 9 Lbs weight.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   Concomitant medication was not provided.  Patient (Physical Therapist) received the first dose of Moderna COVID-19 vaccine on 19 JAN2021 (Lot # 829L20A &  Exp. Date 18JUL2021).  He stated that 2.5 days after the 2nd dose, The patient was presented with Microscopic Colitis  and had  Diarrhea 15 times a day. She was diagnosed with  Microscopic Colitis. She received 2 treatments with Budesonide but after the treatment was done her Diarrhea came back.  Company comment: This is a spontaneous case concerning a 66-year-old female patient with no reported medical history, who experienced the serious  unexpected event Colitis microscopic. The events occurred approximately 3 days after the second dose of mRNA-1273 Moderna vaccine.  Patient had diarrhea and decreased weight and a colonoscopy was performed with diagnosis of Microscopic colitis. Further information has been request. The benefit-risk relationship of mRNA-1273 Moderna vaccine is not affected by this report.; Sender's Comments: This is a spontaneous case concerning a 66-year-old female patient with no reported medical history, who experienced the serious  unexpected event Colitis microscopic. The events occurred approximately 3 days after the second dose of mRNA-1273 Moderna vaccine.  Patient had diarrhea and decreased weight and a colonoscopy was performed with diagnosis of Microscopic colitis. Further information has been request. The benefit-risk relationship of mRNA-1273 Moderna vaccine is not affected by this report.