What to do if no laxative syrup/tab working for constipation.i go to toilet once a day but unable to empty my stomach even once,i feel full all time?

Some other disease?: Each person with constipation needs to be sure there is no other disease causing it. If constipation is just due to slow movement of the food and poop through the gut, things to try are vegetables, prune juice, prunes, fiber+water, polyethylene glycol, Senokot or other senna, milk of magnesia, other laxatives... Make a symptom and "laxatives" diary for the doctor, who might try Linzess or Amitiza.