I've been on the same Kate Farms Peptide 1.5 formula for the past two years, and it's very simply put together. According to them, everything is broken down into its simplest form. And this was the only formula I was able to tolerate, mostly due to its not having any dairy-related components.
(link to formula: https://www.katefarms.com/for-clinicians/products/peptide-1-5-plain-formula/)
Ideally, SIBO is diagnosed with a breath test, but other clues are worse after eating high fiber-containing foods/starches and better avoiding them. I know that this is hard for you to evaluate.
Treatment options are:
Elemental diet- They do make them for feeding tubes. There is one from Integrative Therapeutics that is dairy-free and clean.
Antibiotics- Typically Rifaximin sometimes in conjunction with others
Natural Antimicrobials- There are several options
Anyhow, I know that your situation is challenging with limited resources, so please just ask if you want more info on anything. I don't want to overwhelm. Due to limited motility, SIBO is almost certainly a part of your symptom picture.
Sending you my very best