Grace I took remacaid for several years back 8 -10 years ago while only having severe UC.....4 hour  in hospital infusions once every 2 months first 5 cc. and then with slow results helping my infections increased to 10cc. and went on for almost a year or more before I had a bad reaction while in the infusion process my GI doc said I had built up a resistance to the mouse antibody that Remacaid is made of, the hospital staff watched as I turned red and my blood pressure dropped dangerously, they tore the injection tube out of my arm sent me to the ER and I did not take Remacaid ever again.....as to your question about gaining weight,I never noticed any severe weight changes in 2-3 years of remacaid but I think I always ate more than I should, hence more digestion, and when after the Remacaid the doc tried Humira for some years, sooner or later my system came back with a tight squeezed hole of a blockage that GI could not get endoscope through,decided it looked like pre=cancerous, so they began the J pouch series of surgeries four including one for hernias in my abdomen walls and now, some 6 years since surgery, am now digesting a little less, and gaining a little bit 10 pounds or so, but I exercise, walk, bike ride almost every day, and just this week managed to lose some of the excess pounds………..