hello, welcome to healthcaremagic
i would like to know some more history.
history of trauma?
history of bleeding disorders?
history of strenous exercise?
history of unhealthy food intake in past 2 days?
the cause of pain in your lung area is most probably the
bruise you got diagnosed with. and pain will fade down or take medicine like
diclofenac or
brufen.
the main concern is the reason for formation of bruise. for this please visit a nearby hosp and get full workup done.
secondly
diarrhoea is unrealted to a bruise. anyhow, you should stay hydrated. take ORS after every motion. and also take
racecadotril if diarrhoea is severe. if you feel weak, go to nearby hosp and get a NS/DNS drip.
hope this helps you.
I wish for your good health.
Please feel free to revert back in case of any more doubts/queries.
Thank you.