Stomach and intestinal squeeze do not exist. Those organs
already do a lot of squeezing to move the food and waste along their tract.
Even though the stomach and intestines contain gases, there is no problem
with descending and having Boyle's law cause a contraction of the gases causing
a squeeze.
What about the ascent? Is there a potential for the stomach
and intestines to grow in size creating a barotrauma? It has been written
in many texts on diving that if a diver eats gas-forming foods and descends
to a reasonable depth, the foods will produce gas at the ambient pressure
and that gas would expand upon ascent. Consequently, the stomach and/or the
intestines would over-inflate (explode?). The remedy would be to belch or
flatulate to relieve the pressure. The latter may condemned by fellow
divers.
In the author's entire diving career (since 1954) there
has never been a report of anything related to the stomach and/or the intestines
causing discomfort either on a descent or ascent. Not one of the hundreds
of students, colleagues, and diver acquaintances have ever experienced any
expansion of the stomach or intestines upon ascent. Many have burped and
flatulated during the post-dive period, but that was mostly due to upbringing
and habit!
Throwing up underwater is another matter. This
could have serious consequences! Think of the process: There is the uneasy
feeling, followed by the super-salivary flow, followed by heaving, and then
followed by a shot of stomach contents being projected from the stomach into
and out of the mouth. Next, there is an inhalation of air. The process may
be repeated.
One of the scuba certification agencies reportedly
recommended throwing up into your regulator, removing and replacing it with
the alternate air, and then cleaning stomach remains from the primary. If
the vomiting continued the process could be repeated. Another agency suggestion
was to place the primary regulator mouthpiece next to your mouth and press
the purge button. This would envelop the diver's mouth with a massive amount
of air. The diver would simply throw up into this air stream. Whew! I'm not
sure I would be willing to try either technique!
Fortunately, most divers that experience vomiting on
a dive do so at the surface. The majority of cases get sick on the boat,
or at the surface. There have been a few instances when divers safely
returned to the surface just prior to vomiting. Up until the year 2003
no Deep-Six diver had ever thrown up underwater, nor had there been any other
associated divers that have done it. It is quite rare.
The following is an email sent by a Deep-Six diver in
March 2003. The incident speaks for itself:
"Brian and I just got back a few days ago from a dive
trip to Mexico. We had a great time, but due to storms and current changes
the visibility was not great (between 40' -- 50'). I got to see my first
shark (a 5' black tip reef shark), and got to experience tossing my breakfast
at 85'.
"Here are all the things I did wrong on my 'tossing'
dive:
-
I had just gotten over the flu and was still loaded with antibiotics.
-
Since I had just regained my appetite, I over-ate the night before (and the
breakfast before) my first dive.
-
I forgot to switch my allergy medication cycle from mornings to evenings
(so I was also loaded with allergy medication).
-
Although I only had a few beers the night before, based on just getting over
the flu I should not have had any.
-
The water was extremely rough -- I never get sea sick -- I was feeling a
little ill, but TOLD NO ONE!
-
Even after feeling ill on my descent, I failed to alert my dive buddy (Brian)
that something was wrong at 85'.
-
I failed to get anyone's attention when my stomach began to 'reach the point
of no return'.
-
Although only momentarily, I lost contact with Brian just before tossing
my breakfast (about 12 minutes into the dive).
-
I executed a 360 degree roll to find Brian.
-
After successfully tossing my breakfast at 85' (actually, as it turns out
I only tossed 1/2 my breakfast at 85'), I STILL DID NOT ALERT the dive master
that I was experiencing difficulties (I did, however, alert Brian)
-
After surfacing, I immediately began to toss the other 1/2 of my breakfast
AND FORGOT TO INFLATE my BC.
-
After swimming to the boat, I immediately passed up my weight belt, but failed
to release the shoulder strap on my BC -- as a result I struggled to get
the BC off (fortunately the boat captain immediately reached down and inflated
my BC -- for his trouble he got to wear a little of my "left over" breakfast).
-
After passing up all my equipment, instead of immediately getting on the
boat, I hung onto the side to see if I had actually finished -- the water
was rough and the current was strong -- I'm fortunate I was not separated
from the boat.
"Since my 'style' of 'tossing' is high-volume, projectile,
I removed my regulator in order to 'toss'. I'm sure this was the right thing
to do since I believe I otherwise would have blown the regulator out of my
mouth. I replaced the regulator in my mouth, gave a hard 'clear' (very difficult
to do after nearly fully collapsing my diaphragm), and 'gently' took in a
breath (at first plugging the regulator with my tongue and slowly drawing
in air). The good news is that I was very calm during the entire experience.
I quietly said to my self, 'George said, "You will be OK in nearly every
emergency as long as you don't panic'". After dealing with the emergency
at 85', I truly felt like a fool as I recounted all the things I did wrong
AFTER THE EMERGENCY!
"Although it seems that the natural response to a violent
barf projection is to rebound with a gulp of air (or water if at 85'), I
carefully calculated that my will to live would allow me to suppress the
natural rebound momentarily -- long enough to complete the "clear". I also
counted on an adrenaline serge sufficient to execute the hard 'clear' of
my regulator. Fortunately I was right on both counts. Again, I know my barfing
'style'. There is absolutely no way that the regulator opening was large
enough to handle my volume. Had I kept the regulator firmly in my mouth I
probably would have choked on my vomit and/or forced the excess through my
nose.
"I remembered PADI's recommended method, but recalled
you discussing the alternative I used (either I recalled it or I imagined
it). In any case, not only did I survive the experience, but, if ever faced
with this emergency again, would readily use this same alternative method.
I did have my alternate air out and ready, just in case. I also made sure
I was facing down as I gently took air back in. My thoughts were that if
I had not sufficiently cleared my regulator, the small amount of water that
I took in would rest where gravity placed it -- away from my airway. And,
by-the-way, I turned my regulator face up to establish a visible air flow
before I did the "clear".
"A few minutes after the experience (and still at 85'),
I finally rinsed my mouth with readily available salt water. I truly can't
believe I didn't do it sooner -- talk about leaving a bad taste in your mouth.
"During my descent I actually thought back to my training
with you. I was fully aware that I was running the risk of being sick underwater.
I foolishly had convinced myself that the rough water was the entire culprit
and getting into the water was that right thing to do to settle my stomach
down. Once under water I realized what could possibly happen, I calmed myself,
and did re-runs of the 'tossing' methods you trained me with. Believe it
or not, I actually enjoyed the remainder of the dive -- at least until I
reached the surface.
"Perhaps the most important thing about the experience
is all the things I did wrong, both before and after tossing breakfast. I
took a lot of ribbing from a lot of divers for a few days -- 'Hey, are you
the guy that was feeding the fish', or 'did your chumming the water attract
any fish', or 'were you the guy that...' But, importantly the conversations
ultimately ended up being 'turned' by the other divers. They all genuinely
wanted to know what the experience was like and they all had a ton of questions.
The answers often cost them a beer.
"George, thank you for the great training!!!"