PAROXYSMAL ATRIAL FIBRILLATION; FEELING OR SENSATION OF DRAINAGE IN LEFT NOSTRIL; OCCASIONAL PRESSURE IN BOTH EARS; SLIGHT BURNING SENSATION IN JUST LOWER LIP WITH SMALL, TINY PROTRUSIONS; LOCALIZED BACK PAIN BILATERALLY INFERIOR TO THE POSTERIOR RIB CAGE BUT MOSTLY ON LEFT SIDE; SLIGHTLY HIGH PITCH SOUND IN LEFT EAR; HEADACHE; FATIGUE; SMALL AMOUNT BLOOD IN STOOL; NODULE IN CUBITAL FOSSA AREA ON MEDIAL SIDE OF ARM; SMALL AMOUNTS OF BLOOD IN PHLEGM; IRREGULAR, LESS FREQUENT AND  MORE SOLID BOWEL MOVEMENTS; INCREASED URINATION LASTED 2-3 WEEKS; OCCASIONAL LOCALIZED PRESSURE  AND HEADACHES IN OCCIPITAL, FRONTAL, AND TEMPORAL AREAS; This spontaneous report received from a patient concerned a 66 year old male. The patient's height, and weight were not reported. The patient's past medical history included covid-19 (experienced all the typical symptoms, but waited 13 days to get tested) and concurrent conditions included paroxysmal atrial fibrillation (last time he had an episode until after he received the vaccine). He did not have any recent episodes of atrial fibrillation The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, route of admin not reported, batch number: 1805018, and expiry: UNKNOWN) dose was not reported, 1 total, administered on 29-MAR-2021 to right arm for prophylactic vaccination. No concomitant medications were reported.  On 29-MAR-2021, the patient experienced occasional localized pressure and headaches in occipital, frontal, and temporal areas which were intermittent and pulsating in nature. On APR-2021, the patient experienced small amount of blood in stool and had irregular, less frequent and more solid bowel movements about 2-3 weeks post vaccination. He mentioned around the same time he was urinating more (increased urination lasted 2-3 weeks), and then his bowel movements and urinations became regular again. He also experienced a nodule that appeared in the cubital fossa area on medial side of his arm two weeks after the vaccination and then gradually resolved over 2.5 weeks after it appeared and small amounts of blood in his phlegm which appeared 1.5 weeks post vaccination and he continued to experience this on week 2, week5 post-vaccination and then resolved. On 14-APR-2021, Laboratory data included: Antibody test (NR: not provided) Negative, Complete blood count (NR: not provided) unknown, and Platelet count (NR: not provided) Normal. He reported experiencing 5 episodes of atrial fibrillation within the 7 weeks after vaccination, a diagnosis of paroxysmal atrial fibrillation was confirmed by his cardiologist. He also experienced fatigue about 5-6 weeks after vaccination. He had intermittent waves had fatigue throughout the day which lasts for an hour and then came back later in the day, with no consistency and stated this was still unresolved. (Later on he stated he had no fatigue spells lately and considered this resolved). On an unspecified date, he experienced feeling or sensation of drainage in left nostril, (even though had no excess blood or fluid) which started a few weeks after received the vaccine and then lasted for several months but now resolved and occasional pressure in both ears (opening and closing his mouth did not relieve the pressure) and slight high pitched sound in the his left ear. His ear side effects came and gone and considered them to be resolving but not fully resolved. He noticed a few weeks after vaccination he had slight burning sensation in just his lower lip with small, tiny protrusions (He initially said this was unresolved, but then later said this was resolved). He also experienced localized back pain bilaterally inferior to the posterior rib cage but mostly on the left side. He mentioned he have a checkup next week and will discuss his concerns since this side effect was still unresolved and headache. The patient stated he did not experience any of these side effects before receiving the vaccine. He was generally healthy and tried not to take medication if possible. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient recovered from  paroxysmal atrial fibrillation, nodule in cubital fossa area on medial side of arm, feeling or sensation of drainage in left nostril, slight burning sensation in just lower lip with small, tiny protrusions, and fatigue, and small amount blood in stool, small amounts of blood in phlegm, irregular, less frequent and more solid bowel movements, and increased urination lasted 2-3 weeks on APR-2021, was recovering from occasional pressure in both ears, and slightly high pitch sound in left ear, and had not recovered from headache, localized back pain bilaterally inferior to the posterior rib cage but mostly on left side, and occasional localized pressure and headaches in occipital, frontal, and temporal areas. This report was serious (Other Medically Important Condition).; Sender's Comments: V0: 20210667239-COVID-19 VACCINE AD26.COV2.S. Paroxysmal atrial fibrillation. This event is considered not related. The event has a compatible/suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. There are other factors more likely to be associated with the event than the drug. Specifically: UNDERLYING DISEASE 20210667239-COVID-19 VACCINE AD26.COV2.S. Small amount blood in stool. This event is considered unassessable. The event has a compatible/suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. There is no information on any other factors potentially associated with the event.