SIBO is the result of suppressed stomach acid (hypochlorhydria) by urease positive bacteria or possibly degraded stomach nerve function often a result of low B12 absorption. Once you restore stomach acid production, SIBO should resolve itself.
Have you had a positive test for h. pylori? Actually confirmed it as being present? There are other bacteria which can have very similar effects to h. pylori. A blood test is the better method of detecting it. Urea breath tests are unreliable due to other bacteria. Treating h. pylori if it is not h. pylori could be a failure.
You will have Increased Digestive Permeability aka "Leaky Gut" which is taxing your Liver and using up a limited amount of choline for other purposes leaving insufficient for acetylcholine production which is used to stimulate the bowel.
Be aware that Candida can share a biofilm with gram-negative bacteria such as h. pylori. It could be present in your stomach and spreading from that point. There are other urease positive bacteria besides h. pylori which can setup home (a biofilm) in the stomach.
Ceylon Cinnamon essential oil is effective against candida in very small doses but it can affect Liver S-transferase activity, reducing to 57% in rats. Cinnamaldehyde is the component which is most active against micro-organisms with Eugenol being less active. CC does have some anticancer activity.
Cinnamaldehyde levels can vary widely and CC is sometimes sold with stated levels of this substance. I was looking at one earlier which has at least 60% Cinnamaldehyde, around 75% is the maximum amount that I have seen mentioned. Another one sold by the supplier that I looked at had 45% but some have much less or are not guaranteed.
These bacteria, including h. pylori protect themselves using biofilms. Eliminating the biofilm makes antimicrobials far more effective. Enzymes can degrade a biofilm, things like Interfase/Interfase+, Biofilm Defence, Serrapeptase & Nattokinase. However once they begin to work the micro-organisms will signal to the community to strengthen the biofilm and they can do this as quickly as it can be degraded. That is unless they are prevented from sending their chemical messages which stops them from reinforcing the biofilm which means the enzymes can eliminate it. That leaves them considerably more vulnerable to antimicrobials or Antibiotics .
Their communication is called Quorum Sensing and Quorum Sensing Inhibitors can stop the communication which is very helpful. There are some essential oils which are known to have QSI activity. A compilation of them are in Supreme Nutritions BFB 1 and BFB 2 formulas. Enzymes are needed, I prefer Interfase but it is x2 the price of Interfase+. Interfase+ has less enzymes because some of the capsule space is taken up by EDTA. The EDTA quantity is not really sufficient and I prefer to make my own capsules up using EDTA that can be purchased fairly cheaply. EDTA bind up minerals which are freed when enzymes attack the biofilm and prevents it from being reused to reinforce the biofilm.
The next phase are Efflux Pump Inhibitors to prevent the bacteria from eliminating antimicrobials. There are 5 recognized families of efflux pumps and different micro-organisms use different ones. Antibiotic resistance means these are worth using and mean that smaller doses of antimicrobials are needed. Another option are cell membrane permeabilizers (if that is a word lol), substances to increase or damage the cell membranes of micro-organisms. Cinnamon can do this and so can Turmeric/Curcumin. Capsaicin from peppers is another and there are many more. I have many research papers on all of this but I am not going to list them unless you want them.
Finally some strong antimicrobials targetted at the specific bacteria. Again essential oils are strong, as strong as pharmaceutical Antibiotics . You would need to check for any effect on the liver. Cinnamon is very strong and so is Lemon Grass but finding things which work with the bacteria would be worth doing.
BTW expect some strong discomfort in the stomach once the biofilm drops. I have experienced this twice, once successfully destroying 2/3 of a biofilm and the micro-organisms and once unsuccessfully beating another biofilm micro-organisms which regrew afterwards. Persister cells need to be destroyed for the treatment to be successful. Colloidal Silver is an option but I would avoid ionic silver as it is not effective in the stomach. Reduced CS is more effective and is what destroyed 2/3 of one of the biofilms, whereas ionic silver did absolutely nothing. MesoSilver is meant to be the best.
Essential Oil Safety by Robert Tisserand & Rodney Young is a very good book about Essential Oil toxicity and reported reactions.
Never swallow neat Cinnamon essential oil because it can irritate the mucus membranes. It needs to be put into something such as a capsule before swallowing. I am a little concerned about what will happen when the biofilm drops and the effect against the unprotected stomach lining. I have used Cinnamon but not with an attack against the biofilm therefore it would not of affected the stomach directly.