It takes time for the gut to heal itself. This is not an allergy. With an allergy, take away the offending substance and the reaction stops. In Celiac there has been actual damage to your body. So, even though you have been really conscienctious about avoiding gluten, it still takes time for your gut to heal. Most folks take at least 6 months on the GF diet before they start to see results. It can take up to a year for all the antibody tests to register normal.
The weight gain may be due to the fact that you are now absorbing the nurtrients from your food. Your body is actually getting the nutrition it needs - along with those calories. Try to stay with foods that are naturally gluten free. GF snack foods and even bread tend to be higher in calories than their gluten counterparts.
The abdominal distention is due to the stomach emptying slower than it should. It is called delayed gastric emptying. The reason for this is not completely clear. It is possible that the signals to empty have been distorted or that the small intestine is sluggish and so the food stays in the stomach longer and there is a bloated feeling. It will get better!: -) Also, go easy on things made from bean flour. That can also cause gas and bloating.
Lynn Cicero, M.S., R.D.