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.
