Not a medical opinion, but a search of the Web to find out what this is (as I'd never heard of it) gave the following info regarding diagnosis, etc:
Also known as fainting, syncope (SIN-cuh-pee) is a brief, sudden loss of consciousness. It is a symptom of an underlying cause or condition, not a disease itself. Syncope may be due to harmless causes, or it may be due to more serious underlying cardiovascular or neurologic conditions. Tests that may be run include a tilt table test, which is used to assess neurocardiogenic syncope — fainting due to a reflex that leads to a sudden drop in heart rate and blood pressure. Other tests that may be run include an echocardiogram, a stress test, a Holter monitor (or event monitor), a cardiac catheterization or an electrophysiologic study. In addition, a CT scan or an MRI may be used to evaluate possible neurologic causes. Treatment will depend on the underlying cause that is revealed.
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Syncope is a brief, sudden loss of consciousness. Fainting occurs when the brain is starved for oxygen due to temporarily inadequate blood flow. It can occur after standing up quickly, working or playing too hard, feeling strong emotions or while taking certain medications (e.g., antihypertensives). Syncope is a symptom of an underlying cause or condition, not a disease itself. Often, the underlying cause of a fainting episode cannot be found.
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Micturition syncope. An abrupt loss of consciousness during urination. It often occurs in men whom wake up at night to urinate. The cause is unknown.
I would expect that once the CAA spot this on your form, you should at least be prepared for some heavy duty back-up from your GP / Specialist and most likely an exercise ECG at the minimum. You *definitely* need to talk to an AME about this.