very rarely spreads to stomach and colon
, you have to rule out other causes of stomach pain. Your trating doctor can explore it. Lung cancer does give rise to paraneoplastic syndrome
that might cause frequency of motions. this depends on the particular variety of the lung cancer for which you need to let us know the histopathologic finding of the primary lung leision.
End stage fisigns can not be predicted by the details you have given. For this we need full details as regards history, radiological findings, pathology findings and biochemical findings along with hematological details. Follow up with your physician for supportive management.