Hi thanks for contacting HCM... Pin worm treated by mebendezole tablet .. Single dose of it needed ....Than if no relief you can repeat dose .... So you should had to use drug when infected in past .... Anyway this time get your stool examined for pin worm...If you found thread like worm crawling through anus it is pin worm and treated accordingly... If no pin worm detected than for constipation and gas take stool softener like psyllium in milk... Drink more water ... Avoid sedentery life style .... Fiber food like whole grain , wheat bran , carrot, spinach taken more .... Avoid stress.... Simethicone can taken for gas ... If still constipation USG done to rule out organic causes.... Hope your concern solved..... Take care ....