GASTRITIS; ULCERS; MISSED DOSE; REVACCINATION WITH DIFFERENT COVID-19 VACCINE; SYMPTOMS HAS STARTED TO COME BACK; This solicited report received from a patient via PRIVATE concerned a 31 years old female (patient number: Unknown). The patient's height, and weight were not reported. The patient's concurrent conditions included: Crohn's disease, sulfa allergy, and drug allergy (acetaminophen), and other pre-existing medical conditions included: The patient had illness at the time of vaccination, no past history of similar event, no adverse event after any previous vaccinations, had pre-existing acute illness 30 days prior to vaccinations, had hospitalization in last 30days and not currently breastfeeding. The patient was not pregnant at the time of vaccination.  The patient was treated with ustekinumab (solution for infusion, subcutaneous, batch number was not reported) 1 ml, 1 time every 8 weeks, from JUN-2022, and 90 ml, 1 time every 56 days, from 20-APR-2022 for Crohn's disease. The drug was associated with medication error.  On an unspecified date in 2022, the patient experienced symptoms and had started to come back. On an unspecified date, the patient missed dose.  The patient had previously received three doses of covid-19 vaccine (unspecified manufacturer) (Dose number in series 1) (form of admin and route of admin was not reported, batch number: Unknown, expiry: Unknown) dose was not reported, administered on an unspecified date for covid-19 prophylaxis. It was unknown whether the patient had any adverse events following vaccination with covid-19 vaccine (unspecified manufacturer) (Dose number in series 1). The patient initiated treatment with covid-19 vaccine ad26.cov2.s (Dose number in series 2) (suspension for injection, route of admin, and batch number were not reported) dose was not reported, 1 total, administered at right (site unspecified) on 31-JAN-2023 for covid-19 prophylaxis which was associated with revaccination with different covid-19 vaccine (Dose number in series 2). The batch number was not reported and has been requested. Age at time of vaccination 31 years old. Concomitant medications included estradiol cipionate/medroxyprogesterone acetate for birth control. The patient had gastric distress for which performed capsule study, colonoscopy and endoscopy which showed ulcers and gastritis (Dose number in series 2).  The patient visited the physician office and emergency room. The action taken with covid-19 vaccine ad26.cov2.s was not applicable and action taken with ustekinumab was not reported. The outcome of the symptoms has started to come back, missed dose, gastritis, ulcers and revaccination with different covid-19 vaccine was not reported. The reporter provided no causality assessment. Company causality between covid-19 vaccine ad26.cov2.s, and symptoms has started to come back, missed dose, gastritis, ulcers, and revaccination with different covid-19 vaccine was not related; and between ustekinumab, and symptoms has started to come back, missed dose, gastritis, ulcers, and revaccination with different covid-19 vaccine was not related.  This report was serious (Other Medically Important Condition).  Additional information was received from a patient on 01-MAR-2023. The following information was updated and incorporated into the case narrative: contact as a reporter, patient medical history, suspect vaccine (covid-19 vaccine), concomitant drug, lab tests, event gastritis and ulcers was added.; Sender's Comments: V1: This follow up version updates- patient medical history, suspect vaccine (covid-19 vaccine), concomitant drug, lab tests, event gastritis and ulcers was added. This updated information does not alter the causality of previously reported event.  20221208347-covid-19 vaccine ad26.cov2.s- symptoms has started to come back. The event shows an incompatible temporal relationship. Therefore, this event is considered inconsistent with vaccine administration.  ustekinumab: Crohn's disease. This event(s) is labeled by standard procedures. Therefore, the event(s) is considered not related.