believed was diverticulitis; very sharp lower left pain in my abdomen; Moving and being in certain positions makes it take my breath away; Moving and being in certain positions makes it take my breath away.; extreme tiredness; chills; nausea; aching all over; 102 fever; arthritis aggravated; irritable bowel syndrome aggravated; could barely walk; This spontaneous case was reported by a consumer and describes the occurrence of ABDOMINAL PAIN LOWER (very sharp lower left pain in my abdomen) and DIVERTICULITIS (believed was diverticulitis) in a 72-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 028A21A and 012A21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Drug allergy (allergy to cannibis), IBD (SIBO- IBS - digestive issue(worse since vaccinated)), Joint inflammation (worse since vaccinated), Restless legs syndrome and Penicillin allergy. Concomitant products included ROPINIROLE for Restless leg syndrome.   On 01-Mar-2021 at 11:00 AM, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 29-Mar-2021 at 12:30 PM, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 29-Mar-2021,  after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced ABDOMINAL PAIN LOWER (very sharp lower left pain in my abdomen) (seriousness criterion hospitalization). On 30-Mar-2021, the patient experienced DIVERTICULITIS (believed was diverticulitis) (seriousness criteria hospitalization and medically significant), ARTHRITIS (arthritis aggravated), IRRITABLE BOWEL SYNDROME (irritable bowel syndrome aggravated), GAIT DISTURBANCE (could barely walk), MYALGIA (aching all over), PYREXIA (102 fever), CHILLS (chills) and NAUSEA (nausea). On an unknown date, the patient experienced DYSPNOEA (Moving and being in certain positions makes it take my breath away), POSTURE ABNORMAL (Moving and being in certain positions makes it take my breath away.) and FATIGUE (extreme tiredness). The patient was hospitalized for 2 days due to ABDOMINAL PAIN LOWER. The patient was treated with CIPROFLOXACIN (intravenous) on 31-Mar-2021 for Abdominal pain lower and Diverticulosis, at an unspecified dose and frequency and METRONIDAZOLE (intravenous) on 30-Mar-2021 for Abdominal pain lower and Diverticulosis, at an unspecified dose and frequency. At the time of the report, ABDOMINAL PAIN LOWER (very sharp lower left pain in my abdomen) was resolving, DIVERTICULITIS (believed was diverticulitis), ARTHRITIS (arthritis aggravated) and IRRITABLE BOWEL SYNDROME (irritable bowel syndrome aggravated) had not resolved and DYSPNOEA (Moving and being in certain positions makes it take my breath away), GAIT DISTURBANCE (could barely walk), POSTURE ABNORMAL (Moving and being in certain positions makes it take my breath away.), MYALGIA (aching all over), PYREXIA (102 fever), FATIGUE (extreme tiredness), CHILLS (chills) and NAUSEA (nausea) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 30-Mar-2021, Body temperature: 102 (High) 102. On 30-Mar-2021, Computerised tomogram: abnnormal (abnormal) thickening in colon wall. On 30-Mar-2021, Pain assessment: increased (abnormal) increased from an original 1-2 to a screaming 10+.         It was reported that treatment drug included saline solution for what they believed was either diverticulitus or cytosis and pain medication, a clear liquid diet for the duration of the antibiotics. Patient ate a careful diet of cooked vegetables, some salads and fish or chicken.  Action taken with mRNA-1273 in response to the drug 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.   Most recent FOLLOW-UP information incorporated above includes: On 13-May-2021: added batch no, reporter information, historical condition, concomitant medication, lab data. Suspect drug dosing details were added. Nausea and chills were added as events. Treatment details were updated. Seriousness criteria for Lower abdominal pain was updated. Case is serious (Hospitalization).; 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.