my husband has a blockage between the stomach and the small intestines. the endoscopy did not reveal any kind of tumor , but it was very hard to get the scope through. the doctor thinks it may be due to the radiation he received fighting esophageal cancer . that tumor is gone. when he eats or drinks he becomes full very fast even though he has only eaten or drank a small amount. he cannot have an mri because of the sharpnal that is still in his body from injuries received in veit naim.what kind of test can reveal what this blockage is?