SURGICAL AND GENITOURINARY*
(Photo contributor: Binita R. Shah, MD)
*The authors acknowledge the special contributions of Jennifer H. Chao, MD, and Andrea Marmor, MD, to the prior edition.
Intussusception occurs when the proximal portion of the intestine invaginates into the distal portion, causing abdominal pain, bowel injury, and eventually bowel obstruction. Early in the process, lymphatic return is impeded; then, as the edema and pressure increase, venous followed by arterial flow becomes compromised, leading to infarction of the entrapped bowel segment. Intussusception usually occurs between the ages of 3 months to 3 years, with a peak in infants <1 year old. In children <3 years old, it is generally idiopathic and possibly due to prominent lymphoid tissue in the intestine serving as a lead point. The majority of intussusceptions are ileocolic, although they may present anywhere along the lower gastrointestinal (GI) tract. In older patients, lead points include Meckel diverticula, polyps, tumors (lymphomas or hemangiomas) or intramural edema, and hematomas from Henoch-Schönlein purpura. Sites other than ileocolic are also associated with underlying pathology.
Intussusception. (A) Extreme lethargy was the presenting complaint of this 10-month-old infant. (B) While in the ED, he passed this stool mixed with blood and mucus. Other neurologic signs of intussusception include coma or shock-like state (out of proportion to abdominal signs), seizures, hypotonia, or opisthotonic posturing. (Photo contributor: Binita R. Shah, MD.)
Currant-Jelly Stool in Intussusception. (A) Commercially available currant jelly. (B, C) Diarrhea containing mucus and blood constitutes the classic currant-jelly stool (seen in about 60% of cases). This Hemoccult-positive stool was passed by an 8-month-old infant presenting with inconsolable crying episodes and bilious vomiting. (Photo contributor: Binita R. Shah, MD.)
Intussusception. The apex of the intussusception may extend into the transverse, descending, or sigmoid colon—even to and through the anus, mimicking rectal prolapse. This type of intussusception can be distinguished from rectal prolapse by the separation between the protruding intestine and the rectal wall, which does not exist in rectal prolapse. (Photo contributor: Binita R. Shah, MD.)
Patients typically present with a sudden onset of severe, colicky abdominal pain at regular intervals, vomiting (initially nonbilious, but may progress to bilious), and bloody stool ...