Intussusception is a medical condition in which a part of the

intestine The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The tract is the largest of the body's systems, after the cardiovascular system. T ...

folds into the section immediately ahead of it. It typically involves the

small intestine The small intestine or small bowel is an organ (anatomy), organ in the human gastrointestinal tract, gastrointestinal tract where most of the #Absorption, absorption of nutrients from food takes place. It lies between the stomach and large intes ...

and less commonly the

large intestine The large intestine, also known as the large bowel, is the last part of the gastrointestinal tract and of the Digestion, digestive system in tetrapods. Water is absorbed here and the remaining waste material is stored in the rectum as feces befor ...

. Symptoms include

abdominal pain Abdominal pain, also known as a stomach ache, is a symptom associated with both non-serious and serious medical issues. Since the abdomen contains most of the body's vital organs, it can be an indicator of a wide variety of diseases. Given th ...

which may come and go,

vomiting Vomiting (also known as emesis, puking and throwing up) is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenteritis, pre ...

, abdominal bloating, and bloody stool. It often results in a small bowel obstruction. Other complications may include

peritonitis Peritonitis is inflammation of the localized or generalized peritoneum, the lining of the inner wall of the abdomen and covering of the abdominal organs. Symptoms may include severe pain, swelling of the abdomen, fever, or weight loss. One pa ...

or bowel perforation. The cause in children is typically unknown; in adults a ''lead point'' is sometimes present. Risk factors in children include certain infections, diseases like

cystic fibrosis Cystic fibrosis (CF) is a genetic disorder inherited in an autosomal recessive manner that impairs the normal clearance of Sputum, mucus from the lungs, which facilitates the colonization and infection of the lungs by bacteria, notably ''Staphy ...

, and intestinal polyps. Risk factors in adults include

endometriosis Endometriosis is a disease in which Tissue (biology), tissue similar to the endometrium, the lining of the uterus, grows in other places in the body, outside the uterus. It occurs in women and a limited number of other female mammals. Endomet ...

, bowel adhesions, and intestinal tumors. Diagnosis is often supported by

medical imaging Medical imaging is the technique and process of imaging the interior of a body for clinical analysis and medical intervention, as well as visual representation of the function of some organs or tissues (physiology). Medical imaging seeks to revea ...

. In children,

ultrasound Ultrasound is sound with frequency, frequencies greater than 20 Hertz, kilohertz. This frequency is the approximate upper audible hearing range, limit of human hearing in healthy young adults. The physical principles of acoustic waves apply ...

is preferred while in adults a

CT scan A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...

is preferred. Intussusception is an emergency requiring rapid treatment. Treatment in children is typically by an

enema An enema, also known as a clyster, is the rectal administration of a fluid by injection into the Large intestine, lower bowel via the anus.Cullingworth, ''A Manual of Nursing, Medical and Surgical'':155 The word ''enema'' can also refer to the ...

with surgery used if this is not successful.

Dexamethasone Dexamethasone is a fluorinated glucocorticoid medication used to treat rheumatic problems, a number of skin diseases, severe allergies, asthma, chronic obstructive pulmonary disease (COPD), croup, brain swelling, eye pain following eye su ...

may decrease the risk of another episode. In adults, surgical removal of part of the bowel is more often required. Intussusception occurs more commonly in children than adults. In children, males are more often affected than females. The usual age of occurrence is six to eighteen months old.

Signs and symptoms

Early symptoms can include periodic abdominal pain,

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 d ...

(sometimes green in color from

bile Bile (from Latin ''bilis''), also known as gall, is a yellow-green/misty green fluid produced by the liver of most vertebrates that aids the digestion of lipids in the small intestine. In humans, bile is primarily composed of water, is pro ...

), pulling legs to the chest area, and intermittent moderate to severe cramping

. Pain is intermittent—not because the intussusception temporarily resolves, but because the intussuscepted bowel segment transiently stops contracting. Later signs include rectal bleeding, often with "red currant jelly" stool (stool mixed with blood and mucus), and lethargy. Physical examination may reveal a "sausage-shaped" mass, felt upon palpating the abdomen. Children, or those unable to communicate symptoms verbally, may cry, draw their knees up to their chest, or experience

dyspnea Shortness of breath (SOB), known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing discomfort that ...

(difficult or painful breathing) with paroxysms of pain. In neonates it may present with bilious vomiting and blood stained stools.

Fever Fever or pyrexia in humans is a symptom of an anti-infection defense mechanism that appears with Human body temperature, body temperature exceeding the normal range caused by an increase in the body's temperature Human body temperature#Fever, s ...

is not a symptom of intussusception. However, intussusception can cause a loop of bowel to become

necrotic Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. The term "necrosis" came about in the mid-19th century and is commonly attributed to German pathologist Rudolf Virchow, who is ...

, secondary to

ischemia Ischemia or ischaemia is a restriction in blood supply to any tissue, muscle group, or organ of the body, causing a shortage of oxygen that is needed for cellular metabolism (to keep tissue alive). Ischemia is generally caused by problems ...

due to compression to arterial blood supply. This leads to perforation and

sepsis Sepsis is a potentially life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage of sepsis is followed by suppression of the immune system. Common signs and s ...

, which causes fever. In rare cases, intussusception may be a complication of Henoch–Schönlein purpura, an immune-mediated

vasculitis Vasculitis is a group of disorders that destroy blood vessels by inflammation. Both artery, arteries and veins are affected. Lymphangitis (inflammation of lymphatic vessels) is sometimes considered a type of vasculitis. Vasculitis is primarily c ...

disease in children. Such patients who develop intussusception often present with severe abdominal pain in addition to the classic signs and symptoms of HSP.

Cause

Causes of intussusception are not clearly established or understood. About 90% of cases of intussusception in children arise from an unknown cause. They can include infections, anatomical factors, and altered motility. *

Meckel's diverticulum A Meckel's diverticulum, a true congenital diverticulum, is a slight bulge in the small intestine present at birth and a vestigial remnant of the vitelline duct. It is the most common malformation of the Human gastrointestinal tract, gastrointesti ...

* Polyp * Duplication * Appendix *

Hyperplasia Hyperplasia (from ancient Greek ὑπέρ ''huper'' 'over' + πλάσις ''plasis'' 'formation'), or hypergenesis, is an enlargement of an organ or tissue caused by an increase in the amount of Tissue (biology), organic tissue that results from ...

Peyer's patches Peyer's patches or aggregated lymphoid nodules are organized lymphoid follicles, named after the 17th-century Swiss anatomist Johann Conrad Peyer. * Reprinted as: * Peyer referred to Peyer's patches as ''plexus'' or ''agmina glandularum'' (cl ...

Idiopathic An idiopathic disease is any disease with an unknown cause or mechanism of apparent spontaneous origin. For some medical conditions, one or more causes are somewhat understood, but in a certain percentage of people with the condition, the cause ...

Pathophysiology

In the most frequent type of intussusception, the

ileum The ileum () is the final section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms posterior intestine or distal intestine may ...

enters the

cecum The cecum ( caecum, ; plural ceca or caeca, ) is a pouch within the peritoneum that is considered to be the beginning of the large intestine. It is typically located on the right side of the body (the same side of the body as the appendix (a ...

. However, other types occur, such as when a part of the ileum or

jejunum The jejunum is the second part of the small intestine in humans and most higher vertebrates, including mammals, reptiles, and birds. Its lining is specialized for the absorption by enterocytes of small nutrient molecules which have been pr ...

prolapses into itself. The part that prolapses into the other is called the ''intussusceptum'', and the part that receives it is called the ''intussuscipiens''. Almost all intussusceptions occur with the intussusceptum having been located

proximal Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

ly to the intussuscipiens. This is because

peristaltic Peristalsis ( , ) is a type of intestinal motility, characterized by symmetry in biology#Radial symmetry, radially symmetrical contraction and relaxation of muscles that propagate in a wave down a tube, in an wikt:anterograde, anterograde dir ...

action of the intestine pulls the proximal segment into the distal segment. There are, however, rare reports of the opposite being true. An anatomic ''lead point'' (that is, a piece of intestinal tissue that protrudes into the bowel lumen) is present in approximately 10% of intussusceptions. The lead point (best exemplified by a polyp) serves as a focal area of traction, which the peristaltic action pulls into the distal bowel, thus invaginating the attached bowel segment. The trapped section of bowel may have its blood supply cut off, which causes

(lack of oxygen in the tissues). The

mucosa A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It ...

(gut lining) is very sensitive to

, and responds by sloughing off into the gut. This creates the classically described "red currant jelly" stool, which is a mixture of sloughed mucosa, blood, and mucus. A study reported that in actuality, only a minority of children with intussusception had stools that could be described as "red currant jelly", and hence intussusception should be considered in the differential diagnosis of children passing ''any'' type of bloody stool.

Diagnosis

An intussusception is often suspected based on history and physical exam, including observation of Dance's sign. A digital rectal examination is particularly helpful in children, as part of the intussusceptum may be felt by the finger. A definite diagnosis often requires confirmation by diagnostic imaging modalities.

Ultrasound Ultrasound is sound with frequency, frequencies greater than 20 Hertz, kilohertz. This frequency is the approximate upper audible hearing range, limit of human hearing in healthy young adults. The physical principles of acoustic waves apply ...

is the imaging modality of choice for diagnosis and exclusion of intussusception, due to its high accuracy and lack of radiation. The appearance of target sign (also called "doughnut sign" on a sonograph, usually around 3 cm in diameter, confirms the diagnosis. The image seen on transverse

sonography Medical ultrasound includes diagnostic techniques (mainly imaging) using ultrasound, as well as therapeutic applications of ultrasound. In diagnosis, it is used to create an image of internal body structures such as tendons, muscles, joints ...

computed tomography A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...

is that of a doughnut shape, created by the hyperechoic central core of

bowel The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The tract is the largest of the body's systems, after the cardiovascular system. T ...

and

mesentery In human anatomy, the mesentery is an Organ (anatomy), organ that attaches the intestines to the posterior abdominal wall, consisting of a double fold of the peritoneum. It helps (among other functions) in storing Adipose tissue, fat and allowi ...

surrounded by the hypoechoic outer

edema Edema (American English), also spelled oedema (British English), and also known as fluid retention, swelling, dropsy and hydropsy, is the build-up of fluid in the body's tissue (biology), tissue. Most commonly, the legs or arms are affected. S ...

tous bowel. In longitudinal imaging, intussusception resembles a sandwich. It is also called "pseudokidney" sign because hyperechoic tubular centre is covered by a hypoechoic rim producing a kidney-like appearance.

Classification

* Ileoileal – 4% * Ileocolic (or ileocecal) – 77% * Ileo-ileo-colic – 12% * Colocolic – 2% * Multiple – 1% * Retrograde – 0.2% * Others – 2.8% In children, insussusception at the ileocecal junction accounts for 90 percent of all cases. Topic 5898 Version 37.0

Differential diagnosis

An intussusception has two main differential diagnoses: acute

gastroenteritis Gastroenteritis, also known as infectious diarrhea, is an inflammation of the Human gastrointestinal tract, gastrointestinal tract including the stomach and intestine. Symptoms may include diarrhea, vomiting, and abdominal pain. Fever, lack of ...

and

rectal prolapse A rectal prolapse occurs when walls of the rectum have prolapsed to such a degree that they protrude out of the anus and are visible outside the body. However, most researchers agree that there are 3 to 5 different types of rectal prolapse, depen ...

. Abdominal pain, vomiting, and stool with mucus and blood are present in acute gastroenteritis, but diarrhea is the leading symptom. Rectal prolapse can be differentiated by projecting mucosa that can be felt in continuity with the perianal skin, whereas in intussusception the finger may pass indefinitely into the depth of the sulcus.

Treatment

The condition is not usually immediately life-threatening. The intussusception can be treated with either a barium or water-soluble contrast

or an air-contrast enema, which both confirms the diagnosis of intussusception, and in most cases successfully reduces it.Chowdhury SH, Cozma AI, Chowdhury JH. Abdominal Pain in Pediatrics. Essentials for the Canadian Medical Licensing Exam: Review and Prep for MCCQE Part I. 2nd edition. Wolters Kluwer. Hong Kong. 2017. The success rate is over 80%. However, approximately 5–10% of these recur within 24 hours. Cases where it cannot be reduced by an enema or the intestine is damaged require surgical reduction. In a surgical reduction, the surgeon opens the abdomen and manually squeezes (rather than pulls) the part that has telescoped. If the surgeon cannot successfully reduce it, or the bowel is damaged, they resect the affected section. More often, the intussusception can be reduced by

laparoscopy Laparoscopy () is an operation performed in the abdomen or pelvis using small incisions (usually 0.5–1.5 cm) with the aid of a camera. The laparoscope aids diagnosis or therapeutic interventions with a few small cuts in the abdomen.Medli ...

, pulling the segments of intestine apart with forceps.

Prognosis

Intussusception may become a

medical emergency A medical emergency is an acute injury or illness that poses an immediate risk to a person's life or long-term health, sometimes referred to as a situation risking "life or limb". These emergencies may require assistance from another, qualified ...

if not treated early, as it eventually causes death if not reduced. In developing countries where medical hospitals are not easily accessible, especially when other problems complicate the intussusception, death becomes almost inevitable. When intussusception or any other severe medical problem is suspected, the person must be taken to a hospital immediately. The outlook for intussusception is excellent when treated quickly, but when untreated it can lead to death within two to five days. It requires fast treatment, because the longer the intestine segment is prolapsed the longer it goes without bloodflow, and the less effective a non-surgical reduction is. Prolonged intussusception also increases the likelihood of bowel ischemia and necrosis, requiring surgical resection.

Epidemiology

The condition is more common in children than in adults. It strikes about 2,000 infants (one in every 1,900) in the United States in the first year of life. Its incidence begins to rise at about one to five months of life, peaks at four to nine months of age, and then gradually declines at around 18 months. Intussusception occurs more frequently in boys than in girls, with a ratio of approximately 3:1. In adults, intussusception represents the cause of approximately 1% of

bowel obstruction Bowel obstruction, also known as intestinal obstruction, is a mechanical or Ileus, functional obstruction of the Gastrointestinal tract#Lower gastrointestinal tract, intestines which prevents the normal movement of the products of digestion. Ei ...

s and is frequently associated with

neoplasm A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

malignant Malignancy () is the tendency of a medical condition to become progressively worse; the term is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous benign tumor, ''benign'' tumor in that a malig ...

or otherwise.