What are possible risks and complications of a colonoscopy?

Colonoscopy and polypectomy (polyp removal) are generally safe when performed by doctors who have been specially trained and are experienced in these procedures. One possible complication is a perforation, or tear, through the bowel wall that could require surgery. Bleeding might occur at the site of biopsy or polypectomy, but it's usually minor. Bleeding can stop on its own or be controlled through the colonoscope; it rarely requires follow-up treatment.

Some patients might have a reaction to the sedatives or complications from heart or lung disease. Although complications after colonoscopy are uncommon, it's important to recognize early signs of possible complications. Contact your doctor if you notice severe abdominal pain, fever and chills, or rectal bleeding. Note that bleeding can occur several days after the procedure.

There is a small chance for problems from a colonoscopy. The scope or a small tool may tear the lining of the colon or cause bleeding.

After the test, call your doctor immediately if you:

• Have heavy rectal bleeding.
• Have severe belly pain.
• Develop a fever.
• Are very dizzy.
• Are vomiting.
• Have a swollen and firm belly.