Insoluble fibre makes up most of my carbs as well as the cure, and this flies in the face of everything that we are told about fibre – that insoluble fibre is bad for IBS and is too abrasive for our damaged guts. The truth is, we were meant to eat fibre, in particular the salads that contain insoluble fibre. Many leading researchers believe that IBS is really SIBO, an overgrowth of bacteria in the small intestine. Insoluble fibre bypasses the fermentation process in the small intestine, and is fermented further down by beneficial, colonic bacteria.
Bacteria feed mainly on soluble fibre, and these tend to be the FODMAPs. Bacteria don’t feed much on insoluble fibre, which is mainly composed of tough outer skin that has an abrasive effect on the colon, which helps bowel evacuation. Most people with IBS know this, but think that they can’t tolerate insoluble fibre. The only real way to test this for yourself is to totally exclude all antinutrients and just try the Specific Carbohydrate introductory diet which is based on animal protein and insoluble fibre, but the fibre, carrots, are boiled for 4 hours. This softens a lot of the fibre so it’s not as abrasive.
This diet is designed for people with severe inflammation. It’s a way of gradually introducing fibre, especially insoluble fibre, back into your diet.
Helpful information on insoluble fibre and SIBO: