Your first two examples are for severely abnormal GI function. The latter of the two, EEN, is also a short-term diet that is intended to induce remission of symptoms, at which point presumably whole foods are reintroduced.

Finally, the low FODMAP diet is not intended to eliminate FODMAPs nor is it intended to be used long term. From the inventors of the low FODMAP diet:

"Given the adverse changes in gut microbial populations associated with long-term adherence to a low FODMAP diet, we always encourage people to enter a re-challenge phase and under the guidance of a dietitian, find an acceptable balance between the occasional inclusion of moderate and high FODMAP foods (naturally rich in healthy prebiotics) and adequate symptom control. In the long-term, we advocate people follow the least restrictive diet necessary. Further research into the rechallenge and long-term maintenance phases of the diet is warranted."

https://www.monashfodmap.com/blog/low-fodmap-diet-provides-b...