Los disorders in the small intestine con Very similar symptoms can hide different symptoms. Distension, abdominal pain, gas, diarrhea or constipation appear in more than one of these disorders, but not all of them are explained in the same way.
Three acronyms that are repeated more and more fall into this group: SIBO, SIFO and IMO. Although they are often named together, they are not equivalent. The microorganism involved changes, the mechanism changes and part of the diagnostic approach also changes.
Confusion is quite common because the symptoms overlap. The feeling of a bloated belly, discomfort after eating and altered intestinal rhythm can appear in all three conditions. Therefore, one of the keys is not only the symptoms, but also understanding what type of overgrowth or fermentation is behind it.
That point matters because not everything that causes gas in the small intestine is “the same.” In current clinical practice, SIBO is linked to bacterial overgrowth, ILLNESS with fungal overgrowth and IMO with excess methanogens, a distinct group of microorganisms that is primarily associated with constipation.
He SIBO is bacterial overgrowth in the small intestine. It is related to an abnormal colonization of bacteria in an area where, under normal conditions, the bacterial load is lower than in the colon.
Among the most frequent symptoms are bloating, abdominal pain, flatulence, diarrhea and, in some cases, weight loss or nutritional deficits.
He ILLNESSinstead, points to an overgrowth of fungi in the small intestine. In medical literature it is described above all with a predominance of Candida species.
It can also cause distension, pain, gas and digestive disorders, which is why it is often mixed up in conversations with SIBO although it is not the same painting.
He IMO It is not defined by bacteria or fungi. It refers to overgrowth of intestinal methanogensmethane-producing microorganisms, and not necessarily restricted only to the small intestine. Precisely for this reason, in recent years the idea of separating it from SIBO and name it as a separate entity.
What symptoms and studies are used to differentiate these conditions?
One of the problems of these disorders in the small intestine is that the clinic alone is not enough to separate them precisely. Bloating, gas, pain, belching, diarrhea, or constipation They can be repeated in different combinations. That is why clinical questioning matters, but it does not solve everything on its own.
In SIBO and IMOthe most used study today is Hydrogen-methane breath test, usually with glucose or lactulose as substrate. It is the most widespread non-invasive method, although its interpretation requires clinical context because it is not perfect and can lead to over-reading.
In the case of ILLNESS, the panorama is more complex. There is no validated equivalent breath test as in SIBO or IMO. Medical reviews indicate that the diagnosis is usually supported by aspiration and culture of the small intestine in selected contexts, something much less accessible in normal practice.
