You do not need to reach the large intestine because that is not where your problem lies. The large Intestine is full of biofilms which are not a good idea to interfere with IMO. They protect the bacteria which you got from your mother and early feeding.
It is far easier to reach than that. In fact I would use Interfase because it better addresses biofilms. Interfase plus is meant to be their better product but it is very deceiving because of the 2 forms, none plus and plus versions, the declared the amount of enzymes in the formulas are per capsule and for 2 capsules which make the plus version look better. The Interfase version has a lot more of the necessary enzymes than the plus version and that is because the plus version uses up valuable capsule space with the inexpensive EDTA which is better added to a separate capsule and consumed first of all. Waiting for a couple of minutes before consuming Interfase capsules emptied from their capsules. Do not underestimate the quantity of capsules needed because one is rarely enough, 6, 8 or more can be far better. I take some additional Serrapeptase and Nattokinase as a helpful addition but these do not contain the necessary enzymes to disassemble a biofilm.
I would encapsulate EDTA because you do not want this anywhere near to your teeth. The other enzymes in Interfase should not be a problem for your teeth. Interfase+ does contain EDTA so that should not really be decapped. Interfase+ is quite a bit cheaper than Interfase but IMO it is an inferior product.
Also you will not beat a biofilm without using Quorum Sensing Inhibitors because these can block the communication and prevent them from signalling to re-enforce the biofilm. BFB 1 and BFB 2 are QSI and also have other effects against various micro-organisms such as cell membrane permeablizers and Efflux Pump Inhibitors. EPI's help prevent bacteria/micro-organisms from eliminating antimicrobials. They can dramatically increase an antimicrobials effect and make antimicrobials that were ineffective, effective once again.
If you do this then you will know that you are having success when you feel a discomfort in your stomach. Once that is accomplished, hit it with everything that you can such as highly antimicrobial essential oils, herbs, EPI's. If you are successful then your digestive system will heal very quickly.
There is quite a lot of research on natural antimicrobials such as herbs and essential oils. See my post in the eBooks forum for details on how to access the full research papers.