I have typhoid from a week and i am a heavy smoker ... do smoking causes extrra effect on my stomach?

Yes, it does: smoking may have effects on increasing stomach acid and reflux symptoms, which on top of the inflammation from typhoid fever will increase symptoms. It also may have interactions with some of the antibiotics that are used to treat it, although these are not usually major. Smoking is bad for everything that is good for your health - please consider quitting! Help is available.