CAUSES & CONDITIONS

Jejunoileal Atresia

Types, diagnosis, and surgical management — and how it relates to short bowel syndrome

Jejunoileal atresia is a congenital birth defect with a complete blockage (atresia) or severe narrowing (stenosis) in the jejunum or ileum of the small intestine.

These obstructions result from an intra-uterine vascular accident — a sudden disruption of blood flow in the fetal mesentery that causes a segment of bowel to wither and close off. It affects males and females equally and, unlike duodenal atresia, is usually isolated with fewer associated genetic anomalies.

CLASSIFICATION
Four Structural Subtypes
Type I — Intestinal web

A continuous web-like membrane blocks the lumen. Outer muscular wall stays intact; overall small-bowel length is normal.

Type II — Blind ends with fibrous cord

Blind closed pouch connected to the next healthy segment by a solid fibrous cord. Mesentery remains intact; bowel length develops normally.

Type III — Separated blind ends

Blind ends fully separated with a V-shaped mesenteric gap. Lost bowel is reabsorbed, significantly shortening overall length. Type IIIb (“apple-peel” or “Christmas tree”) wraps remaining bowel around a single fragile artery and carries a high risk of Short Bowel Syndrome.

Type IV — Multiple atresias (“string of sausages”)

Multiple successive blocked sections interspersed with healthy tissue. Dramatically reduces functional intestinal length.

CLINICAL
Signs & Symptoms

A complete small-bowel obstruction triggers distress in the first days of life:

Bilious vomiting — dark green bile. High jejunal blockage: within first 24 hours. Ileal blockage: may delay 2–3 days
Abdominal distension — visibly swollen belly as gas and fluid pool behind the obstruction
Failure to pass meconium — typically no first dark stool within 24–48 hours

DIAGNOSIS
Diagnostic Protocols
Prenatal

Polyhydramnios — excess amniotic fluid on ultrasound, because the blocked fetal gut cannot swallow and process fluid normally.

Abdominal X-ray

Often first postnatal step. Shows dilated air-filled small-bowel loops with no air in the lower colon.

Lower GI contrast series

Contrast enema maps rectum and colon, often revealing a tiny unused colon (microcolon) and the level of obstruction.

Upper GI contrast series

Used when high jejunal or duodenal obstruction is suspected.

Abdominal ultrasound

Assesses real-time intestinal movement and mesenteric blood flow. Heart or kidney imaging may be added if other anomalies are suspected.

SURGERY
Surgical Treatment

Definitive correction requires emergency surgery under general anesthesia. Technique depends on atresia type.

Type I repair

Incision over the internal web, excision of the membrane, and longitudinal closure (jejunoplasty). Unhealthy segments may be resected.

Types II–IV repair

Blind ends are resected. Dilated upper bowel is often tapered so its width matches the distal segment, then ends are joined (primary anastomosis).

CONNECTION TO SHORT BOWEL SYNDROME

Type III (especially apple-peel) and Type IV atresias can leave critically short residual bowel. These infants may need intestinal rehabilitation, parenteral nutrition, and long-term specialized care.

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Note
This information is for educational purposes only and is not a substitute for professional medical advice. Always consult your medical team for diagnosis and treatment decisions.