The conditions overlap. The tests disagree. Nobody selling you something will say so.
Low Reactive is an independent reference for people stuck between SIBO, histamine intolerance, MCAS and the conditions that shade into them. We are not a clinic and we do not sell a supplement line, which means we can say the thing the rest of this search results page cannot: a great deal of this is genuinely unsettled.
Where our numbers come from
Every count on this site is measured against a corpus of 695,050 posts and 7,205,554 comments from 18 patient communities, 2011 to 2026. We publish the exact query behind each one, so you can check it rather than trust it. The corpus, and what is wrong with it.
Start with what you are actually trying to tell apart
We rank these by how often real patients discuss the two together, not by what we guess people search. The number beside each is measured.
- IBS or SIBO?16,408 comments discuss both
All 36 pairs we measured, including the ones we chose not to write about
The fact that costs people the most money
Of the 5 breath tests we track, 1 measures hydrogen sulfide. The other 4 cannot detect it at all. So a person buys the cheaper test, gets a negative, and concludes they do not have SIBO, when the test was structurally incapable of finding one of the three gases. That happens constantly and almost nothing on the internet prevents it.
Which test measures what, with prices and dates
Where to go next
- Is it this or that?Differential diagnosis at the overlaps. Which conditions readers actually confuse, measured from 7.2 million patient comments.
- TestsWhat each breath test can physically measure, what it costs, and what a negative result does not rule out.