Swallowed objects, such as toothpicks, chicken bones, or fish bones, may become lodged at the junction between the anus and rectum (anorectal junction). Also, enema tips, surgical sponges or instruments, thermometers, and objects used for sexual stimulation may become lodged unintentionally in the rectum after being passed through the anus.
Sudden, excruciating pain during bowel movements suggests that a foreign object, usually at the anorectal junction, is penetrating the lining of the anus or rectum. Other symptoms depend on the size and shape of the object, how long it has been there, and whether it has perforated (pierced) the anus or rectum or caused an infection.
A doctor can feel the object by probing with a gloved finger during an examination. An abdominal examination, sigmoidoscopy (see Endoscopy), and x-rays may be needed to make sure the wall of the large intestine has not been perforated.
If a doctor can feel the object, a local anesthetic is usually injected under the skin and lining of the anus to numb the area. The anus can then be spread wider with an instrument called a rectal retractor, and the object can be grasped and removed. Sometimes doctors give general anesthesia, which relaxes the anus and allows the object to be removed without surgery. Natural wave-like movements of the wall of the large intestine (peristalsis) generally bring higher foreign objects down, making removal possible.
Occasionally, if a doctor cannot feel the object or if the object cannot be removed through the anus, exploratory surgery is needed. The person is given a regional or general anesthetic so that the object can be gently moved toward the anus or so that the rectum can be cut open to remove the object.
After the object is removed, the doctor does a sigmoidoscopy (a flexible tube is inserted into the anus to view the lower portion of the large intestine, the rectum, and the anus) to determine whether the rectum has been perforated or otherwise injured.
Last full review/revision October 2014 by Parswa Ansari, MD