never digest vegetable type matter, some type of cancer?

Hi, im 34 years old male , 6'2" and 195 lbs. i have increased belching and gurgling stomach (especially when i first wake up) for about 5 months and lots of undigested vegetables in my stool (this symptom ive had for years). Ive lost about 15 lbs during this time. I was on aciphex for years because of gerd but was switched to dexilant for gastritis. Ive recently stopped taking the dexilant and am trying bentyl 4x a day but so far no changes. i am very regular with my bowel movements (once a day) so i dont see how it could be ibs. these are the tests i have done so far: chest xrays (normal), ekg, cbc, liver and pancreas enzyme blood tests (all normal), upper gi series (showed some thickening of rugal folds), upper endoscopy with biopsy (mild gastritis and gerd, negative on celiac and h pylori), gallbladder ultrasound (normal), ct scan of abdomen and pelvis with contrast (normal), colonoscopy (normal) and hida scan with cck (normal). I do have health anxietys and am currently in therapy and taking vybrid for anxiety. Im curious why i never seem to digest vegetable type matter, seeds and nuts. I guess my question could all of this just be a combination of gerd slight ibs and high levels of stress and anxiety. with all of these tests wouldnt they have seen if something serious was causing my symptoms? I worry about some type of cancer, but if cancer was causing symptoms wouldnt some test have seen it? Thank you