Colitis/ Lymphocytic colitis; Diarrhea on and off every day/ Chronic diarrhoea; Sore arm; Listlessness/tiredness; This spontaneous case was reported by a consumer (subsequently medically confirmed) and describes the occurrence of COLITIS MICROSCOPIC (Colitis/ Lymphocytic colitis) in a 66-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 001A21A and 032L20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included GERD, Alcohol use (1 to 2 drinks per day, 2 to 3 times a week), Caesarean section on 13-May-2013, Colonoscopy in June 2013, Foot surgery (hammer toes/bunion) on 13-May-2013 and Colonoscopy (Mild colitis ascending, transverse and descending in continuous fashion. Path: microscopic colitis with background of acute inflammation in all segments even rectal biopsies.) on 22-Apr-2021. Concurrent medical conditions included Hypertension, Hypercholesterolemia, Diabetes and Caffeine consumption (1-2 cups per day). Concomitant products included DOXYCYCLINE HYCLATE for Diarrhea, MULTIVITAMIN [VITAMINS NOS], METOPROLOL SUCCINATE, METFORMIN HCL, LISINOPRIL, SIMVASTATIN and BALSALAZIDE DISODIUM for an unknown indication.   On 22-Jan-2021 at 3:30 PM, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 22-Feb-2021 at 3:30 PM, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 22-Feb-2021, the patient experienced PAIN IN EXTREMITY (Sore arm) and FATIGUE (Listlessness/tiredness). On 28-Feb-2021, the patient experienced DIARRHOEA (Diarrhea on and off every day/ Chronic diarrhoea). On an unknown date, the patient experienced COLITIS MICROSCOPIC (Colitis/ Lymphocytic colitis) (seriousness criterion medically significant). The patient was treated with COLESTIPOL HCL (oral) ongoing since an unknown date for Colitis, at a dose of 1 g twice a day; LOPERAMIDE HYDROCHLORIDE (IMODIUM) ongoing from 06-Mar-2021 for Diarrhea, at an unspecified dose and frequency and DOXYCYCLINE ongoing since an unknown date at an unspecified dose and frequency. On 24-Feb-2021, PAIN IN EXTREMITY (Sore arm) and FATIGUE (Listlessness/tiredness) had resolved. On 01-May-2021, DIARRHOEA (Diarrhea on and off every day/ Chronic diarrhoea) had resolved. At the time of the report, COLITIS MICROSCOPIC (Colitis/ Lymphocytic colitis) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 16-Mar-2021, Culture: negative (Negative) Negative. On 16-Mar-2021, Cytology: negative (Negative) C diff negative. On 16-Mar-2021, Giardia test: negative (Negative) Negative. On 16-Mar-2021, Haemoglobin: 13.8 (normal) Hb 13.8. On 16-Mar-2021, Helicobacter test: negative (Negative) Negative. On 16-Mar-2021, Mean cell volume: 92 (Inconclusive) 92. On 16-Mar-2021, Platelet count: 269 (Inconclusive) 269. On 16-Mar-2021, Stool analysis: elevated (High) Lactoferrin elevated and 523 (Inconclusive) Calprotectin 523. On 26-Apr-2021, Blood pressure measurement: 120/72 (normal) BP 120/72 mmHg. On 26-Apr-2021, Body temperature: 98.1 (normal) 98.1 F. On 26-Apr-2021, Heart rate: 80 (normal) 80/min. On 26-Apr-2021, Oxygen saturation: 98 (normal) 98%.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   On 22-Feb-2021, the patient experienced sore arm and tiredness after the 2nd vaccine dose. On 28-Feb-2021, she started to have acute diarrhea, up to 8x a day.  The diarrhea had continued until May 1st, although the number of bowel movements (BM) per day had lessoned to 1-2 x.  The patient had seen her doctor, who ordered blood work, stool sample, and an abdominal ultrasound.  On 01-Apr-2021, she saw a gastro specialist. On 13-Apr-2021, she had a colonoscopy.  As of 01-May-2021, all symptoms had resolved.  Lab data : USG and Blood test were done and the results were not provided.  Treatment included to avoid NSAIDS, colestipol recurrent symptoms and budesonide if persistent.  The patient received both scheduled doses of mRNA-1273 prior to the events; therefore, action taken with the drug in response to the events was not applicable.  Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.   This case was linked to MOD-2021-128061 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 18-May-2021: Added patient demographics, medical history (GERD, Colonoscopy, C-section, Foot surgery), labs (Lactoferrin+, Claprotectin, H pylori, Culture, Giardia, C diff, Hb, MCV, PLT, Temperature, BP, HR, Oxygen sat), site of vaccine administration, concomitant medications (Multivitamin, Metoprolol succinate, Simvastatin, Metformin HCl, Doxycycline Hyclate, Lisinopril, Balsalazide Disodium), events (Colitis, Lymphocytic colitis). On 01-MAY-2021 the event (Chronic diarrhea) resolved.; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.