Dr. Thankappan has got more than 40 years of experience as Gastroenterologist and Hepatologist. He studied in Govt. Medical College Trivandrum. He worked in various capacities as Lecturer, Assistant Professor, Associate Professor and Professor from 1979 onwards. He also worked as Professor and Head of the Department of Gastroenterology and Hepatology for 5 years in Narayana Medical College, Nellore He then worked as consultant Gastroenterologist in the Kingdom of Saudi Arabia under the Ministry of Health for 2 years. He has been involved in the Investigation of epidemics of hepatitis in Idukki , Kattappana and Kollam. Dr.Thankappan was an assistant editor in prestigious book Chronic pancreatitis in India edited by Prof. Dr.V.Balakrishnan (Late). He contributed chapters in the book of common problem in Gastroenterology, Practical Gastroenterology etc. Dr. Thankappan is regularly performing upper GI Endoscopy, colonoscopy, sigmoidoscopy- both diagnostic and therapeutic procedures. At present working as a senior consultant and chief of gastroenterology in Ananthapuri Hospitals and Research Institute, Trivandrum.