Thank you for the query.
Unexplained weight loss
should be always checked with possible cancer. Constipation
can be always a sign of large intestine
issues including colon cancer. It is more possible especially if you have also blood in stool, abdominal pain, nausea.
Urobilinogen in the urine can indicate bile ducts obstruction for example. With this condition, the stool should get pale.
I suggest you to visit your doctor
and have abdominal CT, blood work, Ca 125, CEA, Ca 19,9, colonoscopy, gastroscopy and gynecologist consult. If you smoke, chest CT should be also done.
Hope this will help.