Felt very weak within 24 to 30 hours of vaccine/symptoms were "getting better but started all over again" after she received the second shot; Distinct prolonged/protracted episodes of diarrhea for about 2 months and was still slight issue; Stomach cramps/symptoms were "getting better but started all over again" after she received the second shot; Low grade fever within 24 to 30 hours of vaccine/symptoms were "getting better but started all over again" after she received the second shot; Chills within 24 to 30 hours of vaccine/symptoms were "getting better but started all over again" after she received the second shot; Minor nausea/symptoms were "getting better but started all over again" after she received the second shot; This spontaneous case was reported by a physician and describes the occurrence of ASTHENIA (Felt very weak within 24 to 30 hours of vaccine/symptoms were "getting better but started all over again" after she received the second shot), DIARRHOEA (Distinct prolonged/protracted episodes of diarrhea for about 2 months and was still slight issue), ABDOMINAL PAIN UPPER (Stomach cramps/symptoms were "getting better but started all over again" after she received the second shot), PYREXIA (Low grade fever within 24 to 30 hours of vaccine/symptoms were "getting better but started all over again" after she received the second shot) and CHILLS (Chills within 24 to 30 hours of vaccine/symptoms were "getting better but started all over again" after she received the second shot) in a 73-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Irritable bowel syndrome and Arthritis. Concomitant products included LOPERAMIDE for Diarrhea.   On 19-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 19-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On an unknown date, the patient experienced ASTHENIA (Felt very weak within 24 to 30 hours of vaccine/symptoms were "getting better but started all over again" after she received the second shot), DIARRHOEA (Distinct prolonged/protracted episodes of diarrhea for about 2 months and was still slight issue), ABDOMINAL PAIN UPPER (Stomach cramps/symptoms were "getting better but started all over again" after she received the second shot), PYREXIA (Low grade fever within 24 to 30 hours of vaccine/symptoms were "getting better but started all over again" after she received the second shot), CHILLS (Chills within 24 to 30 hours of vaccine/symptoms were "getting better but started all over again" after she received the second shot) and NAUSEA (Minor nausea/symptoms were "getting better but started all over again" after she received the second shot). At the time of the report, ASTHENIA (Felt very weak within 24 to 30 hours of vaccine/symptoms were "getting better but started all over again" after she received the second shot), DIARRHOEA (Distinct prolonged/protracted episodes of diarrhea for about 2 months and was still slight issue), ABDOMINAL PAIN UPPER (Stomach cramps/symptoms were "getting better but started all over again" after she received the second shot), PYREXIA (Low grade fever within 24 to 30 hours of vaccine/symptoms were "getting better but started all over again" after she received the second shot), CHILLS (Chills within 24 to 30 hours of vaccine/symptoms were "getting better but started all over again" after she received the second shot) and NAUSEA (Minor nausea/symptoms were "getting better but started all over again" after she received the second shot) outcome was unknown.        For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   The patient got product via intramuscular injection in deltoid.  No concomitant product use was provided by the reporter.  Treatment medication included the patient sought medical attention from her gastroenterologist, which caller states was "reassuring", and had since been taking a "tiny amount" of 2mg loperamide anti-diarrheal tablet when needed, which helps the symptoms.    This case was linked to MOD-2021-333370 (Patient Link).