Hi, Sorry to know about the condition. Your mother might be probably suffering from food pipe narrowing. Blockage seems to be not a possibility. It it is secondary to less blood, I would suggest to get a blood examination done and to look for microcytic hypochromic anemia and Ferritin values. This anemia secondarily can lead to condition called as Plummer Vinson Syndrome - combination of post cricoid dysphagia (difficulty in swallowing) and esophageal webs along with iron deficiency anemia. If none of the above is present, I would myself suggest Upper endoscopy to rule out any other pathological cause. Take care Hope I was helpful. Happy to help any queries in future.