Colon cancer at age 30 would be unlikely. That said, any persistant change in the caliber of the stool would warrant futher investigation.
The best test to evaluate for colon cancer would be a
colonoscopy. You can also consider a flexible sigmoidoscopy as well.
Regarding intestinal obstruction, plain films of the abdomen can be done to evaluate this. If there continues to be suspicion, a CT scan would be the approprate test for more detail.
You may want to discuss these options with your personal physician.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
Medical Weblog:
kevinmd_b