How do I know perforated colon cause from cancer or diverticulitis?

Perforation. Acute perforation can be caused by acute diverticulitis or colon cancer. Shen there is a perforation emergency surgery is required and the removal of the perforated segment of colon is reviewed by a pathologist which can help differentiate between colon cancer and diverticulitis.
Colonoscopy. If you've had a perforation the GI doctor can tell if there is cancer of diverticulitis on a colonoscopy. A ct may also be useful.
Colon perforation. Colon perforates you become ill and require hospitalization. Cancer and diverticulitis are causes and surgery is often needed. If during colonoscopy, a perforation related to the scope occurs, you might not be ill as you had a bowel prep and the perforation is usually not related to underlying colon pathology. Observation and no food for 12 hours.

Related Questions

What would cause a perforated colon if not diverticulitis?

Several causes. Cancer, stercoral ulcer (hard stool which erodes through the bowel, obstruction (a blocked colon will usually perforate at the right side [cecum], )trauma, ulcerative colitis, and toxic megacolon associated with clostridia difficile infection, are all possible causes of colon perforation. Read more...
Many things. Poor blood flow, foreign objects, ulcers, severe constipation (stercoral ulcers), .... Many many things. Read more...