Complaints & connections · borters.ch
Too many bacteria in the small intestine, where few belong — that explains bloating soon after eating.
Also known as: SIBO · small intestinal bacterial overgrowth
Open in the tool — with search and all the links →This compilation is for information and replaces neither medical diagnosis nor treatment. If you have symptoms, see a doctor.
In SIBO, too many bacteria settle in the small intestine, where normally only a few live. They ferment food already there, causing bloating, abdominal pain and altered stools. SIBO usually arises as a consequence of another cause — impaired gut motility, after surgery or with an underlying illness. The boundaries are not settled: the usual breath tests are imprecise, and not every digestive complaint is SIBO. So a careful work-up matters more than a hasty self-diagnosis.
Between meals a wave runs through the small bowel and clears it out. If it fails — through constant snacking, braking medicines or a nerve disorder — that is the most common mechanical explanation for an overgrowth.
SIBO is usually secondary — treating the underlying problem (e.g. motility) is key against relapse.
A gut-acting antibiotic (e.g. rifaximin), prescribed, is the standard treatment.
Some benefit temporarily from an adapted diet (e.g. low-FODMAP) — guided, not permanent and not alone.
Not every bit of bloating is SIBO. Breath tests are uncertain — have symptoms assessed medically.
Wind, loose stool and weight loss after a journey or after spring water look confusingly like small-bowel overgrowth. Three stool samples or an antigen test separate the two before antibiotics are decided on.
Rifaximin stays in the gut and lowers the number of organisms — in about half, symptoms improve for some months. It does not remove the cause: as long as the movement of the small bowel or the valve to the colon is not right, it comes back, in many within six to nine months. So after the course the question is the cause — motility, adhesions, thyroid, drugs that quieten the bowel.
The breath test runs two to three hours with readings every fifteen to twenty minutes; a rise of twenty ppm of hydrogen within ninety minutes counts as abnormal. Treatment lasts ten to fourteen days. In about half, the picture improves for some months; in many it returns within six to nine months if the cause remains. The small bowel’s sweeping cleaning reflex runs only between meals — four to five hours between meals gives it time.
Distended belly, often after eating and building up over the day.
Cramps, diarrhoea or constipation, sometimes alternating.
With pronounced SIBO, deficiencies are possible (e.g. vitamin B12) — hence a work-up makes sense.
The bacteria in the small bowel use up B12 before the body can take it in. A low value without another explanation fits the picture.
The same bacteria produce folate — so it can be high here while B12 is low. This combination is a clue in its own right.
An iron shortage without loss of blood is among the consequences of disturbed uptake in the small bowel.
It falls with marked malabsorption. A normal value speaks for the nutrition still arriving on the whole.
Soluble fibres like psyllium and oats bind water and make the stool supple. Wheat bran and a lot of raw vegetables, by contrast, increase bloating and pain in a sensitive gut — this distinction explains most of the failures.
Taken up right at the end of the small bowel and needing a helper from the stomach. If either place is affected a deficiency arises — often only after years, because the liver holds a store.
Fibre without water makes the stool harder instead of softer. The two belong together, and the effect only sets in after some days.
Taken up in the upper small bowel and needing stomach acid. Acid blockers, an inflamed lining and silent blood losses often come together here.
Draws water into the bowel and therefore works with a sluggish stool. The belly shows the upper limit: if the stool gets too loose, the dose at once was too high.
Relaxes the gut muscle and eases the cramping. 0.2–0.4 ml three times daily over 4 weeks is the studied frame. It does not act on the overgrowth itself.
Here as a warning: prebiotics also feed the bacteria in the wrong place. In SIBO they regularly worsen bloating — one of the few cases where less fibre is temporarily right.
Clearly worthwhile and well supported when deficient — vegan, older adults, certain drugs. No energy boost without a deficiency.
Clearly effective with proven deficiency, useless without. Take only with a documented deficiency — excess is harmful.
Effective when deficient; effects on sleep and stress plausible but moderate. Too much causes loose stool.
The heart of the matter: between meals a cleaning wave runs through the small intestine, set off by this hormone. If it fails — through diabetes, scleroderma, opioids or constant snacking — bacteria stay where they do not belong.
The stomach acid is the first barrier against bacteria from food. Acid blockers over years take that barrier away — one of the most common and most easily overlooked contributions.
An underactive thyroid slows the gut and favours the overgrowth. The value belongs in with stubborn bloating, before the third round of antibiotics begins.
The cleaning wave only starts 90–120 minutes after the last meal. 4–5 hours between meals and a longer night gap give it time; constant snacking interrupts it.
Often eases symptoms quickly but does not fix the overgrowth. 2–6 weeks, then rebuild.
Temporarily reducing fermentable carbohydrates is studied — as a test phase, not as a permanent diet.