Suggest Treatment For Cough Syncope
Cough syncope
Detailed Answer:
I read your question carefully and I appreciate your concern about your friend.
It is a known phenomenon that during coughing spells there may be a syncope as a complication. It is a phenomenon which is more common in young adult men, so your friend perfectly fits that description. A syncope is a transient loss of consciousness due to temporary lack of blood supply to the brain. Lack of blood supply means lack of oxygen supply, so you're right in your reasoning. Increased pressure on the diaphragm is present as well as you suggest, although not because of the abdominal scar as you think, but because of the contraction of the abdominal muscles while coughing leading to increased pressure inside the abdomen which may make diaphragm expansion more difficult.
The mechanism for the cough syncope is because cough can stimulate the parasympathetic component of the autonomic nervous system which regulates heart rate and blood pressure, so in turn it slows down heart rate and lowers blood pressure leading to the syncope. A syncope may even lead to seizures at times, but the origin is in the low blood pressure making the brain suffer secondarily, not related to an issue of the brain itself.
So I think the origin of these coughing and sneezing spells must be sought after (may be an allergic issue) in order to prevent them from happening. Naturally your friend must be convinced about that in order to have the appropriate tests. Heart function must be also evaluated with an ultrasound and EKG. For the seizure hypothesis, brain imaging and EEG are the necessary tests but as I said I consider that track as the least likely.
I remain at your disposal for other questions.
Thank you.
Detailed Answer:
I am pleased to have somewhat eased your concern. I hope you friend will be better soon.