Some patients wake
up with a relatively flat abdomen but develop dramatic abdominal distension as
the day progresses. According to neurogastroenterology and GI motility
specialist Dr Zubin Sharma, the explanation may be more complex than simply
“too much gas”.
It
is a symptom many patients find difficult to explain.
They
wake up in the morning with a relatively normal abdomen. Breakfast seems
manageable. By afternoon, the stomach begins to expand. And by evening, the
abdomen may appear so distended that clothes no longer fit comfortably.
Some
patients describe looking “five or six months pregnant”.
Yet
scans may be normal. Endoscopy may reveal no major abnormality. Dietary changes
provide inconsistent relief.
According
to Dr Zubin
Sharma, a gastroenterologist specialising in GI motility and
neurogastroenterology, one of the biggest misconceptions about bloating is that
it is always caused by excessive gas.
“Bloating
and visible abdominal distension are related, but they are not exactly the same
symptom,” says Dr Zubin Sharma. “And in some patients, the amount of gas in the
intestine does not fully explain how dramatically the abdomen changes.”
The
answer may lie in understanding how the abdominal wall, diaphragm, intestine
and nervous system interact.
Bloating Is
a Sensation. Distension Is a Physical Change
Patients
frequently use the words bloating and distension interchangeably.
Medically,
there is an important distinction.
Bloating
is the sensation of abdominal pressure, fullness or swelling.
Abdominal
distension is a measurable or visible increase in abdominal girth.
A
patient may feel severely bloated without obvious abdominal enlargement.
Another may develop striking visible distension during the day. Some experience
both.
According
to Dr Zubin Sharma, identifying the dominant symptom is an important part of
evaluating difficult bloating.
“When
a patient says, ‘My stomach is bloated’, I want to know what exactly they
mean,” he explains. “Is it pressure? Fullness? Pain? Visible enlargement? Does
it increase after meals? Is the abdomen flat again the next morning?”
These
details can provide clues about the underlying mechanism.
Is Excess
Gas Really the Problem?
The
conventional explanation for bloating is straightforward: gas accumulates
inside the intestine and pushes the abdomen outward.
Sometimes
this is correct.
Fermentation
of certain carbohydrates by intestinal bacteria can produce gas. Constipation
may influence intestinal gas handling. Food intolerances and other digestive
conditions can also contribute to symptoms.
But
research in disorders of gut-brain interaction has shown that the story is not
always this simple.
Some
patients with severe bloating do not necessarily produce dramatically more
intestinal gas than people without symptoms.
The
difference may lie in how the body senses and responds to intestinal contents.
“Two
people can have a similar physiological stimulus in the intestine and
experience it very differently,” says Dr Zubin Sharma. “Intestinal sensation
and the body's muscular response can influence the final symptom.”
This
is where neurogastroenterology enters the picture.
When the
Diaphragm and Abdominal Wall Respond Differently
One
particularly interesting mechanism associated with visible abdominal distension
is abdominophrenic dyssynergia.
The
term sounds complicated. The basic concept is surprisingly logical.
Normally,
the diaphragm and abdominal wall muscles coordinate to maintain the shape and
pressure of the abdominal cavity.
In
some patients with abdominal distension, this muscular response appears to
change.
The
diaphragm may descend while the anterior abdominal wall relaxes. The abdominal
contents are redistributed. The abdomen visibly protrudes.
Dr
Zubin Sharma explains that this does not mean the patient is deliberately
pushing the stomach outward.
“It
is a physiological pattern of muscular coordination,” he says. “The patient is
not consciously creating the distension.”
This
may explain why some patients develop dramatic changes in abdominal appearance
despite investigations failing to demonstrate a corresponding massive increase
in intestinal gas.
Why
Restrictive Diets Can Become a Trap
Patients
with chronic bloating frequently begin eliminating foods.
First
dairy. Then gluten. Then lentils. Then fruit. Vegetables disappear.
Eventually,
the patient may be surviving on a very narrow list of foods considered “safe”.
Dr
Zubin Sharma believes indiscriminate dietary restriction can become
counterproductive.
“Diet
is extremely important in managing bloating, but restriction should have a
clinical purpose,” he says. “Removing ten different food groups without
understanding the mechanism can create nutritional and psychological problems.”
Structured
dietary interventions, including selected use of fermentable carbohydrate
restriction, may help appropriate patients.
But
diet is only one component of treatment.
Constipation,
visceral hypersensitivity, altered gut-brain processing and abnormal muscular
responses may also contribute.
For
Dr Zubin Sharma, the central question remains the same: what is driving the
symptom in this particular patient?
The
Gut-Brain Axis Does Not Mean the Symptom Is Imaginary
Patients
with chronic bloating are sometimes told that their symptoms are caused by
anxiety or stress.
The
relationship between the brain and digestive system is scientifically
established.
But
Dr Zubin Sharma cautions against using the gut-brain axis as a dismissive
explanation.
“The
gut-brain axis is biology,” he says. “It involves neural signalling, intestinal
sensation, autonomic responses and changes in gastrointestinal function.”
In
disorders of gut-brain interaction, the nervous system may process signals
arising from the intestine differently.
Normal
physiological events can become uncomfortable or painful. Muscular responses
may also be altered.
Understanding
these mechanisms allows treatment to move beyond the simplistic argument of
whether a symptom is “physical” or “psychological”.
Dr Zubin
Sharma Believes Difficult Bloating Needs a Mechanism-Based Approach
Through
his work in neurogastroenterology and gastrointestinal motility,
Dr Zubin Sharma frequently evaluates patients whose digestive symptoms remain
unexplained despite extensive investigations.
He
believes severe bloating should be assessed systematically.
Doctors
must first identify alarm features and exclude relevant structural or organic
disease where appropriate.
The
patient's bowel pattern, relationship of symptoms to meals and presence of
visible distension should then be carefully understood.
Selected
patients may require evaluation for constipation, disorders of gut-brain
interaction or other abnormalities of gastrointestinal function.
Treatment
can subsequently be directed towards the dominant mechanism.
This
may involve dietary modification, treatment of constipation, therapies
targeting intestinal sensation, behavioural strategies or specialised
retraining techniques in selected patients.
“The
objective is not to tell every bloating patient that they have the same
disorder,” says Dr Zubin Sharma. “The objective is to understand why that
particular patient is bloated.”
Bloating Is
More Complicated Than “Gas”
For
patients who develop dramatic abdominal distension every evening, the
explanation may not fit inside a simple bottle of antacid or digestive enzyme.
The
intestine is part of a complex physiological system involving sensation,
movement, muscles and the nervous system.
Dr
Zubin Sharma believes greater awareness of these mechanisms could change how
difficult bloating is treated in India.
Because
sometimes the question is not simply:
“Which
food is producing gas?”
The
more useful question may be:
“Why
is the body responding to the gut in this way?”
And
for patients who have spent years eliminating foods and repeating normal
investigations, that may be an entirely new way of understanding their
symptoms.