hi there, your history is a little vague but what I understand is that you have stomach pain due to parasitic infection
and it is not relieved by taking medication. First of all you should know the type of parasitic infection and accordingly take medication for it. If it is worm infestation in the stomach which can also give rise to pain then you could try deworming yourself with antihelmenthics like tab Zentel
one in the night and then repeat it again after 15 days and see if it gives you any relief. As for the butt pain well you need to get and move around every two hrs if you are sittling for a long time in fromt of the computer. also some form of exercise would increase the blood circulation and stop these symptoms. You could try some stretches standing up . Hope these simple measures help. Take care.