Small Bowel Injury

First steps after a belly injury

1. Call 911 or your local emergency number for any significant crash, fall or penetrating injury.
2. Keep the person still and lying down. Do not give food or drink, in case surgery is needed.
3. Cover any open wound with a clean, moist dressing. If bowel is visible, do not push it back in.
4. Do not remove an impaled knife or object.
5. After any high-speed crash with a lap-belt bruise, get checked at a trauma center even if pain seems mild.

Why small bowel injuries happen

The small intestine is about 20 feet (6 meters) long and fills most of the belly. It is the hollow organ most often injured in abdominal trauma.

• Blunt trauma: a sudden force crushes a loop of bowel against the spine, bursts a fluid-filled loop like a balloon, or tears the bowel from its fixed points. Lap belts worn across the belly instead of the hips, bicycle handlebars and direct blows are typical causes.
• Penetrating trauma: knives and bullets frequently injure the small bowel because it occupies so much of the abdomen. Gunshot wounds often cause multiple holes.
• Mesenteric injury: tears in the fan of blood vessels supplying the bowel cause bleeding and can cut off blood flow, so a segment of bowel dies and perforates days later.

The seat belt sign

A bruise or abrasion across the lower belly from a lap belt is called the seat belt sign. It significantly raises the chance of a hollow organ injury and is often seen with a fracture of the lumbar spine (a Chance fracture). Children who sit in adult belts without a booster seat are at particular risk, because the belt rides up onto the soft belly.

Symptoms

• Belly pain, which may start mild and steadily worsen
• Tenderness, especially when the belly is pressed and released
• A rigid, board-like belly (peritonitis)
• Nausea and vomiting
• Fever and a fast heart rate, as infection develops
• Swollen belly and no passing of gas
• Bruising on the belly wall, or wounds

Delayed symptoms are a hallmark: a small tear may leak slowly, so the first exam can be reassuring. That is why people with significant belly trauma are re-examined over many hours.

Diagnosis

• Physical examination, repeated over time by the same team when possible
• CT scan with contrast: the main test. Signs include free fluid without a liver or spleen injury, free air, thickened bowel walls and leaking contrast. CT can miss small bowel injuries, especially early.
• FAST ultrasound at the bedside to look for fluid or blood in the belly, mainly to detect bleeding
• Blood tests: white cell count, lactate and, in some cases, repeated over time
• Diagnostic laparoscopy or laparotomy: looking inside the belly directly when tests are unclear and suspicion remains, or right away for gunshot wounds and unstable patients

Treatment

Surgery

Nearly all full-thickness small bowel injuries need surgery, as with any bowel perforation:

• Primary repair: small holes are cleaned and stitched closed.
• Resection and anastomosis: a damaged or devascularized segment is removed and the healthy ends joined.
• Damage control surgery: in critically injured patients, bleeding and contamination are controlled first, and the bowel is reconnected in a second operation 24 to 48 hours later after stabilization in intensive care.

Surgery may be done through a standard incision or laparoscopically in stable patients.

Supportive care

• Intravenous fluids and blood products as needed
• Antibiotics to treat contamination
• Pain control and nutrition support while the bowel recovers
• Treatment of associated injuries to the spleen, liver, colon or spine

Non-surgical management

Minor bowel wall bruises (hematomas) without perforation are sometimes managed with observation, bowel rest and repeated scans, especially in children with duodenal hematomas.

Complications

• Peritonitis and abscesses
• Sepsis
• Leak from the repair (anastomotic leak)
• Wound infection
• Prolonged ileus (the bowel stops moving for days)
• Adhesions causing bowel obstruction months or years later
• Short bowel syndrome if large lengths must be removed (rare)

Delays in diagnosis of more than about 8 to 24 hours are associated with more complications and a higher risk of death.

Outlook

Most people recover well after prompt repair, with a hospital stay of about 5 to 10 days for an isolated injury. Recovery is longer with multiple injuries or peritonitis. Long-term problems are uncommon, although adhesions can cause blockages later in life.

Prevention

• Wear the lap belt low across the hips, not the belly, and the shoulder belt across the chest.
• Use car seats and booster seats until the adult belt fits correctly, usually when a child is about 4 feet 9 inches (145 cm) tall and 8 to 12 years old.
• Children under 13 should ride in the back seat.

Frequently asked questions

Can a small bowel injury be missed?

Yes. Small tears may cause only mild pain at first, and CT scans can look nearly normal early on. That is why doctors re-examine people with significant belly injuries over many hours and why worsening pain, vomiting or fever after discharge needs prompt return to the ER.

What is the seat belt sign?

It is a bruise or scrape across the lower belly caused by a lap belt during a crash. It signals that a large force went through the abdomen and is linked to injuries of the small bowel, colon and lumbar spine. Anyone with this sign needs a careful trauma evaluation.

How long after an accident can bowel injury symptoms appear?

Most cause symptoms within the first 24 hours, but signs can be delayed by a day or more, particularly if the blood supply is damaged and the bowel wall slowly dies before perforating. Seek care for any belly pain that develops or worsens in the days after an injury.

Do all small bowel injuries need surgery?

Full-thickness tears and perforations almost always do, because leaking bowel contents cause peritonitis. Bruising of the bowel wall without a hole can sometimes be managed by observation, bowel rest and nutrition support, with surgery if the person gets worse.

What is the recovery time after small bowel repair surgery?

Most people stay in the hospital for about 5 to 10 days and return to normal activities over 4 to 6 weeks. Heavy lifting is avoided for about 6 weeks after an open operation. Recovery takes longer when there are other injuries or infection.