Colon Injury (Large Bowel Injury)

First steps after an abdominal injury

1. Call 911 for any significant abdominal injury, even if the person feels well initially. Bowel injuries can take hours to show symptoms.
2. Do not remove any object stuck in the abdomen. Stabilize it with padding.
3. Cover any wound with a clean, moist dressing; if bowel protrudes, cover it with a clean, moist cloth and do not push it back.
4. Keep the person lying still and warm. Do not give food or drink.

How the colon gets injured

The colon is about 1.5 m (5 feet) long and runs around the abdomen. Because it contains a high concentration of bacteria, any hole allows stool to contaminate the abdominal cavity, causing peritonitis and potentially sepsis.

Penetrating trauma

Gunshot and stab wounds cause most traumatic colon injuries. The transverse colon is most often hit because of its position across the front of the abdomen.

Blunt trauma

Less common but harder to detect. Mechanisms include:

• seatbelt injury: the lap belt compresses the bowel against the spine in a sudden stop, sometimes with a bruise across the abdomen (seatbelt sign) and a spinal fracture (Chance fracture)
• direct blows from handlebars, sports or assaults
• crush injuries
• falls from height

Blunt injury can tear the bowel wall or its blood supply (mesentery), causing delayed perforation days later.

Iatrogenic injury (from medical care)

• colonoscopy: perforation occurs in roughly 1 in 1,000 to 1 in 3,000 diagnostic procedures, more often with polyp removal or dilation
• abdominal, gynecological or urological surgery
• enemas or rectal tubes
• foreign bodies inserted through the rectum

Symptoms

• abdominal pain and tenderness, often increasing over hours
• a rigid, board-like abdomen or pain worse with any movement (peritonitis)
• abdominal swelling (distension)
• fever and chills
• nausea and vomiting
• blood from the rectum
• signs of shock: fast pulse, low blood pressure, confusion
• shoulder tip pain, from free air or blood irritating the diaphragm

After colonoscopy, perforation symptoms usually start within 24 to 48 hours but can be delayed.

Diagnosis

Trauma teams assess patients using trauma protocols. Tests may include:

• CT scan with contrast: the main test in stable patients, showing free air, fluid, bowel wall thickening and contrast leak
• Focused ultrasound (FAST): detects free fluid in unstable patients
• Exploratory laparotomy or laparoscopy: for penetrating wounds with peritonitis, instability or uncertain imaging; often both diagnostic and therapeutic
• Blood tests: blood count, lactate, kidney function and blood typing

Grading

The American Association for the Surgery of Trauma grades colon injuries from I to V:

Treatment

• Primary repair: stitching small, non-destructive tears. Now used for most penetrating colon injuries, based on trauma society guidelines.
• Resection and anastomosis: removing the damaged segment and joining the ends.
• Resection with colostomy: the healthy end is brought out through the abdominal wall as a stoma, used for severe injuries, shock, heavy contamination or major other injuries. The colostomy can often be reversed after 2 to 6 months.
• Damage control surgery: in critically injured patients, a short operation controls bleeding and contamination, with definitive repair after stabilization.
• Antibiotics covering bowel bacteria.
• Colonoscopy perforations: small perforations recognized during the procedure can sometimes be closed with endoscopic clips. Others need surgery.

Complications

• intra-abdominal abscess
• anastomotic leak (the join breaks down)
• wound infection
• sepsis and organ failure
• hemorrhagic shock from associated injuries
• bowel obstruction from adhesions later

Outlook

Most patients with isolated colon injuries recover well with timely surgery. The outlook worsens with delayed diagnosis, heavy contamination, shock and multiple injuries. Recovery after laparotomy usually takes 6 to 8 weeks.

Frequently asked questions

What are the symptoms of a perforated colon?

The main symptoms are severe, worsening abdominal pain, a tender and rigid belly, fever, abdominal swelling, nausea and vomiting. Some people have rectal bleeding or signs of shock. A perforated colon is an emergency needing immediate medical care.

Can a car accident injure the colon?

Yes. A lap seatbelt can compress the bowel against the spine during a sudden stop, causing tears or damage to its blood supply. Symptoms may develop hours or days later, so abdominal pain after a crash, especially with seatbelt bruising, needs prompt assessment.

How common is colon perforation during colonoscopy?

It is rare, occurring in roughly 1 in 1,000 to 1 in 3,000 diagnostic colonoscopies, with a higher risk when polyps are removed. Call your doctor or go to the ER for worsening abdominal pain, swelling or fever after a colonoscopy.

Will I need a colostomy after a colon injury?

Not always. Most colon injuries are repaired directly or by removing the damaged section and rejoining the ends. A temporary colostomy is used for severe injuries or when the patient is very unwell, and can usually be reversed months later.