@vanessab – I feel so bad for your husband! I went without a proper diagnosis for close to 10 years – then to find out I had 2 rare, not connected GI disorders. OK now. Has he been tested for celiac disease? Many of his symptoms point to that. Celiac is an autoimmune disease, often co-existing with hypothyroidism. Also, have all his pituitary hormones been checked? Food allergies?
Don’t give up. If you have not done so already, consider going to a major university hospital or Mayo Clinic. I went to Mayo for years.