Thanks your your query.
Though it is difficult to prove ,your description of event closely matches to what is called vasovagal syncopal attack or micturition syncope
Micturition (or post-micturition) syncope is fainting
during or, more commonly, immediately after urination due to a severe drop in blood pressure.
The exact cause of micturition syncope isn't fully understood. But it may be related to opening (vasodilation
) of the blood vessels that occurs when getting up and standing at the toilet or that occurs at the rapid emptying of a full bladder. This is thought to result in a sudden drop in blood pressure.
The additional factors contributing are fatigue
, hunger, dehydration
Hope I satisfied your query.