I would maybe seek alternative sources of fat/energy that may be easily digested so as to stop your body from burning your reserves (fat deposits etc). Not sure the dosage, but--if it were me--I would take a lot of extra virgin coconut oil (3-5 tbls) or a MCT supplement (medium chain triglycerides) from an online mega retailer at 30+% off (brand I would try: NOW)--again, not too sure on dosage but at least six caps of those for your situation. I am in no way qualified to tell you how much, but you cannot overdose or anything.
From there, I would ask people their thoughts on the easiest/effective liquid nutrition protocol (elemental, enteral nutrition etc.) or at least get most of your nutrition from liquids/smoothies. I personally like the green goodness bolthouse farms juice or the carrot juice or a vege-mix (tomato base mix) in conjunction with plain kefir milk or plain yogurt. Aside from those, I would eat easily digested proteins like hard boiled eggs. When I exclusively follow that food regime, I personally don't have any problems whatsoever, as long as I take my daily enteric coated fish oil (nearly 4 grams actual omega 3) and mix up my probios (taken 3 times daily, I like Jarrow EPS or livingstreamsmission.com liquid probiotic which I alternate). I have no scientific basis, it just works for me.
My extreme protocol involves practically fasting for a day and a half starting the morning with Sonnes #7 1tbls of bentonite clay. From there, as best I can I only eat coco oil/MCTs along with a greens supplement like garden of life's Perfect Food, twice a day, along with forementioned probios/fish oil and basically empty/reset my bowels while perhaps adding a prebio fiber like acacia root or NOW Pau D'Arco. Lots of water too. Then start the above liquids/eggs routine.
Not sure if this applies but I would maybe scan my summary of a todaysdietician article below for pointers, especially consider taking pancreatin and/or an ox bile supplement as well as fat soluble vitamins/supplements (maybe digestive enzyme complex also):
From todaysdietician: "FODMAPs to avoid include fructose (eg, high-fructose corn syrup, agave syrup, honey, apples, pears); lactose (milk, yogurt); fructans (wheat, barley, ry, onions, garlic); galactans (legumes); and polyols (sugar alcohols, mushrooms, cauliflower, avocados, stone fruits)."
"In cases of steatorrhea, the presence of excess fat in the stool, the use of medium-chain triglycerides (MCTs) from coconut oil and MCT oil or supplementation with ox bile can facilitate the digestion and absorption of fatty acids and liposoluble nutrients."--not sure if ox bile is similar to animal sourced pancreatin, my comment.
The article,"Treatment and Management of SIBO", by Aglaee Jacob is pretty good. They say small intest bacteria overgrowth interferes with absorption of all fat soluble vitamins (a, d, e, k) as well as omega 3s, coQ10, B12, iron and beta carotene.
They offer supplemention with MCTs, ox bile, Omega 3s, L-glutamine, zinc, and vitamin A, as well as avoiding gluten/gliandin, starches and sugars, as ways to heal the intestines while avoiding FODMAPs above.
--I am in no way saying do any or all the above, just adding my two cents for you to parse through. Good luck.