Irritable bowel or other (intolerances, SIBO, LGS, etc.)? Here are some medical indications

By Cristiano Antonino On Mar 27, 2023

Irritable bowel syndrome is a functional disorder that affects one in three people, mostly women, and is characterised by disturbances referred to the colon (cramps, spasms, diffuse or localised pain in a specific point of the abdomen), constipation, diarrhoea, meteorism

These symptoms can be variously associated with each other.

Those affected often experience a real drama as they are affected in their social relationships and incessantly turn from one specialist to another in search of a solution.

The diagnosis of irritable bowel syndrome

The various specialists frequently, after assessing whether it is coeliac disease or irritable bowel syndrome and excluding other real (i.e. organic) pathologies of the digestive system (such as gallstones, gastritis, ulcers, diverticula, inflammatory colitis, polyps, tumours), conclude in favour of a diagnosis of irritable bowel and propose therapeutic remedies to the patient aimed at controlling the symptoms, but which are often not controlled.

But what most depresses the patient is being told phrases such as: ‘calm down because it is a simple irritable bowel related to anxiety, work stress; a nice holiday and everything will be resolved’.

But it will not. That is why patients fall into utter despair and resume their tour of hope in search of new specialists.

A review of the literature, which is very sensitive to this globally important issue, shows that the term irritable bowel syndrome is often abused and used by doctors as an escape route to label certain intestinal disorders whose cause cannot be found.

It is true that real irritable bowel exists and that sometimes psychotherapeutic support is needed, but sometimes the solution is just around the corner if one thinks of the many pathological conditions (in addition to the organic ones listed) that can give symptoms quite similar to those of the irritable colon.

What if it is not irritable bowel syndrome?

A growing body of literature points the finger at food intolerances and the state of intestinal flora as misunderstood causes that can develop irritable bowel-like symptoms.

Here are the conditions that are recommended for further investigation.

Non-Celiac Gluten Sensitivity (NCGS)

This is a new pathological entity that brings together those patients who are not affected by coeliac disease (negativity of specific antibodies and histological normality of the duodenal villi), but who when taking gluten have the same disorders as coeliacs (abdominal pain, meteorism, diarrhoea, etc.).

For gluten sensitivity there are no diagnostic tests, but improvement or disappearance of symptoms with the discontinuation of gluten is valid as proof.

Gluten sensitivity is reversible.

Lactose intolerance

Lactase depletion is present in 30 % of Caucasians and more than 70 % of Asians.

Lactase is an enzyme present on the edge of intestinal cells whose activity decreases from pre-school to adulthood, making it difficult or impossible to digest milk and dairy products.

Deficiency of this enzyme results in the intestine’s inability to break down the complex sugar, lactose, the disaccharide found in cow’s, goat’s and donkey’s milk, into two simple sugars: glucose and galactose that can be assimilated by the intestine.

The symptoms of lactose intolerance are very similar to those of irritable bowel syndrome.

Intolerance to FODMAP foods

FODMAP (a term coined in 2001 by a group of researchers at the University of Melbourne) stands for Fermentable Oligo-, Di- and Mono-saccharides and Polyols, a series of short-chain carbohydrates such as lactose, fructose, galactans and polyols. Saccharides include fructose, lactose, fructan and galactan.

Polyols are sorbitol, mannitol, xylitol and maltitol.

These carbohydrates, contained in many foods, can be poorly absorbed by the small intestine and rapidly fermented by intestinal bacteria in the ileum and proximal colon.

Symptoms are due to distention of the intestine either through a high volume of retained fluid due to the process of osmosis or through increased gas production.

This process is responsible for a symptomatology similar to that of the irritable colon.

Altered intestinal permeability syndrome (Leaky Gut Syndrome – LGS)

The intestine forms a real barrier that allows the absorption of nutrients useful to our organism and the rejection, on the other hand, of other substances such as macromolecules, toxins, pathogens and allergenic substances. Under certain conditions (unhealthy eating habits, medication or stress) an alteration of this barrier can occur and this is accompanied by local symptoms (such as irritable bowel syndrome with diarrhoea) and systemic symptoms from inflammatory states and immune system reactions (multiple hypersensitivities to food, skin erythema, respiratory symptoms such as asthma, allergic symptoms, chronic fatigue, poor concentration, especially after meals, joint pain or arthritis, etc.).

Small Intestinal Bacterial Overgrowth Syndrome (SIBO)

This is a situation characterised by an exaggerated growth of bacteria in the small intestine (at least 10 – 15 times the normal) with a simultaneous change in the strains of the bacterial population that becomes very similar to that of the colon.

The symptoms are very non-specific with intestinal disorders, quite similar to those of the irritable colon, and systemic (malabsorption, weight loss, anaemia, etc.).

It should be borne in mind that it is not at all uncommon to have both SIBO and altered intestinal permeability syndrome simultaneously.

On the contrary, usually those who suffer from SIBO over a long period of time will later develop permeable bowel.

Is it irritable bowel syndrome? What to do?

The above shows how easy it really is to confuse one of the listed situations with irritable bowel syndrome.

This is why the authors of a recent paper advise, when assessing a patient with IBS, to always consider food intolerances (FODMAP), intestinal permeability syndrome and SIBO, after having excluded ‘real’ gastrointestinal pathologies.

Irritable bowel syndrome may also be present, but the other conditions only accentuate and persist the symptoms.

Some advice for patients

If you present with symptoms that might suggest irritable bowel syndrome, it is advisable:

Do not rely on the multitude of food intolerance tests (which are expensive and unreliable), but follow the instructions of the specialist doctor.

Face this pathology calmly in the knowledge that it can be resolved (or at least controlled) and that it will never evolve into a ‘bad’ disease (polyps, Crohn’s, tumour, etc.).