Talk to Gastroenterologist on GASTRIC AND STOOL ISSUES

hi i am having gastric issues for a long time. i have consulted dr at ziaudding he gave me 2 sachet and 1 capsule dose but problem is still there. i cant eat spicy food. most of the i face gas issues with stool pass. also i get continus burps. kindly suggest me good and suitable doctor. the doctor at ziaddun directly asked me to do sigmodoscopy test . i am afraid . i have red the symptons of stomach cancer and it has became my nightmare . kindly suggest me good doctor who is good and feeable . pls thanks