I'd like to respectfully make you aware of some imprecisions in your statements.
https://en.wikipedia.org/wiki/Neuromuscular-blocking_drug
https://en.wikipedia.org/wiki/Anesthesia_awareness
Specifically, neuromuscular blockers is what you seem to be referring to. Those paralyze only muscle, not other organs, and therefore have little influence on intestines. They are of multiple uses to both the anesthesiologist (intubation) and surgeons (easier to reach places normally crammed up by active muscle).
There are ways to reduce intestinal activity specifically, but those are not very efficient (glucagon).
As for awareness situations, you are right in that they are more likely with neuromuscular blockers on board. However, research shows that the surgical context is of great importance, and situations where:
- the patient is perceived as most fragile (cardiac surgery)
- or where things go too fast (emergency C-section)
are most at risk, due respectively to fear of overdose in fragile patients and immediate threat to life to the unborn child.
Detection of true awareness is difficult, since many people will tell you they woke up during surgery while it was in fact the end of surgery (from personal experience). It is not known how frequent true awareness really is, but it is commonly accepted to be quite rare, and this goes along with my personal experience.
If you are reasonably healthy, the chance of true awareness during surgery is IMO vanishingly small.
Civil war soldiers did indeed not have neuromuscular blockers, but since efficient sleep medication did not exist, true awareness was far more frequent (probably the norm, in fact).