DIARRHEA; STOMACH CRAMPS; platelets decreased; This spontaneous case was reported by a consumer and describes the occurrence of PLATELET COUNT DECREASED (platelets decreased), DIARRHOEA (DIARRHEA) and ABDOMINAL PAIN UPPER (STOMACH CRAMPS) in a 75-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 025L20A) for COVID-19 vaccination.    Co-suspect product included non-company product ADALIMUMAB (HUMIRA) for Crohn's disease.    The patient's past medical history included Diarrhea in 2011, Stomach cramps in 2011, Polyp removal and Radiation exposure.  Concomitant products included PREDNISONE, NIACIN and MESALAMINE for an unknown indication.   In 2018, the patient started ADALIMUMAB (HUMIRA) (Subcutaneous) 40 milligram. On 13-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. In February 2021, ADALIMUMAB (HUMIRA) (Subcutaneous) dosage was changed to 40 milligram once a week. On 14-Jan-2021, the patient experienced PLATELET COUNT DECREASED (platelets decreased). On an unknown date, the patient experienced DIARRHOEA (DIARRHEA) and ABDOMINAL PAIN UPPER (STOMACH CRAMPS). In February 2021, PLATELET COUNT DECREASED (platelets decreased) and DIARRHOEA (DIARRHEA) had resolved. In 2021, ABDOMINAL PAIN UPPER (STOMACH CRAMPS) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In December 2020, Platelet count: 200000 no unit. On 14-Jan-2021, Platelet count: dropped to 100,000. In February 2021, Platelet count: normal.     mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosing remained unchanged.       Formulation of Humira was reported as Solution for injection in pre-filled pen.  Patient started drinking alcohol 60 years ago.  He did not have any history of occupational exposure to chemicals and inhalants. He did not have any prior use of immunosuppressant and antineoplastic use. From 2011, the patient had diarrhea and cramping which was going on. He was switched to weekly dosing in Feb 2021 due to bi-weekly not working and ongoing diarrhea and cramping. He received covid vaccines and wanted to report that after first shot, his platelets dropped to 100,000. But later returned to normal.  He was taking a statin medication, two blood pressure pills, and other over-the-counter medicines. He stated that it was a total of ten concomitant medications including supplements. He mentioned that all of his problems were gone after the second dose of Covid 19 vaccine. He did not experience any associated symptoms or signs of malignancy. There were no radiation and chemotherapy treatments. Weekly dosing of HUMIRA working well as of 26 Aug 2021. He had small ulcers around ileum were gone. He had squamous cell in upper ear, would have surgery to remove. It was unknown if patient was enrolled in a COVID 19 Vaccine Trial.  This case was identified as part of a retrospective clean-up activity where certain emails received in the Moderna mailbox were missed to be booked-in.      Most recent FOLLOW-UP information incorporated above includes: On 13-Sep-2021: Added medical history, event, concomitant medication, Humira dosage details, lab data and updated Moderna vaccine dates. On 17-Dec-2021: Updated causality and added events.