Inflammatory Bowel Disease (IBD) and Small Bowel Obstruction

1. Introduction: Inflammatory Bowel Disease (IBD) and Small Bowel Obstruction. Inflammatory Bowel Disease (IBD) encompasses conditions like Crohn’s disease and ulcerative colitis, which are characterized by chronic inflammation of the digestive tract.

Individuals with IBD are at a higher risk of developing complications like small bowel obstruction.

In this article, we’ll explore the risk factors, symptoms, diagnosis, treatment options, when to consult a doctor, and preventive measures related to IBD and small bowel obstruction.

Strictures, or abnormal narrowing of the intestine, are a common complication of Crohn’s disease (CD) and can lead to partial or complete obstruction. Historically, as many as 71% of patients with CD require surgery within 10 years of diagnosis, and over half of these surgeries are for obstruction. In fact, intestinal obstruction is the most common complication of small bowel CD.

There are three different phenotypic behavior patterns of CD: nonstricturing/nonpenetrating, stricturing, and penetrating. Stricturing CD is the most common type, especially in patients diagnosed at a younger age and in those with ileal disease. Strictures are also more common at anastomotic sites between the small and large intestines. Pure colonic strictures are less common.

There are many risk factors associated with surgery in CD, but patients with stricturing and obstructing CD are more likely to require surgery if they have an enteroenteric fistula, proximal small bowel dilation greater than 3 cm, or an abscess/phlegmon. Additionally, up to 87% of patients with ileocecal disease eventually require resection for stricture.

Unfortunately, the rate of recurrence of symptoms over time is relatively high, with Toh et al. estimating a 36% rate of symptomatic recurrence.

Risk Factors for Small Bowel Obstruction in IBD

Extent of Inflammation:

• The location and extent of inflammation within the digestive tract can impact the likelihood of developing obstructions. Continuous inflammation over time may lead to narrowing of the bowel, increasing the risk.

Fistulas:

• Fistulas are abnormal connections or tunnels that can form between different parts of the digestive tract in IBD. These can contribute to obstructions.

Prior Abdominal Surgery:

• Individuals with a history of abdominal surgery, especially surgeries related to IBD, may be more prone to developing adhesions or strictures that can lead to small bowel obstruction

Symptoms of Small Bowel Obstruction in IBD

When small bowel obstruction occurs in individuals with IBD, they may experience symptoms such as:

• Severe abdominal pain and cramping
• Abdominal bloating
• Nausea and vomiting
• Constipation
• An inability to pass gas
• Audible bowel sounds

Acute Obstruction VS Chronic Small Bowel Obstruction due to Crohn’s disease: 

Acute Obstruction:

In Crohn’s disease (CD), acute inflammation of the intestine that causes obstruction is more likely to respond to medical treatment.

However, about 75% of patients with an acute Crohn’s stricture will eventually need some type of intervention, either endoscopic or surgical.

Acute strictures are caused by swelling of the bowel wall, as opposed to the scarring that causes chronic strictures.

High-quality imaging tests, such as computed tomography enterography (CTE) and magnetic resonance enterography (MRE), can often help to distinguish between acute and chronic stricture.

Researchers found that patients with the following three MRE characteristics had a poorer prognosis despite maximum drug therapy and were more likely to require surgery:

• Bowel wall thickening of >10 mm at the stricture
• Stricture length of >5 cm
• Prestenotic dilation of >30 mm

The positive predictive value of these three factors in combination was 81%. Conversely, the majority of patients were able to avoid surgery if none of these features were present, with a negative predictive value of 83%.

High-quality imaging can help clinicians to counsel patients and understand the likelihood of treatment success.

Risk factors for acute Crohn’s flares are thought to include cigarette smoking, nonsteroidal anti-inflammatory drug use, antibiotics, infections, and

Chronic Obstruction 

Strictures and obstructions are common in Crohn’s disease, especially in the small intestine. They usually happen over time and are not cancerous.

However, if a large bowel stricture or obstruction occurs, it could be cancer.

Most Crohn’s obstructions are caused by chronic strictures that are hardened and fibrous. There is no medication to specifically target this type of stricture, so surgery is often needed.

Fibrosis is a process that causes tissue to become hardened and scarred. It can occur in all layers of the bowel wall in Crohn’s disease.

There are many different mechanisms that can lead to fibrosis, and they are not fully understood. This makes it difficult to develop targeted drug therapies.

Malignant strictures (cancerous strictures) are rare in Crohn’s disease, but they are more common in the colon than in the small intestine.

The risk of colorectal cancer is higher in patients with Crohn’s disease than in the general population.

Diagnosis of Small Bowel Obstruction in IBD

Diagnosing small bowel obstruction typically involves a combination of methods:

Medical History:

• The healthcare provider will review the patient’s medical history, especially their history of IBD and any prior abdominal surgeries.

Physical Examination:

• A physical examination can reveal signs of abdominal tenderness and distention.

Imaging Studies:

• Imaging tests such as X-rays, CT scans, or MRIs can help visualize the site and cause of the obstruction.

Blood Tests:

• Blood tests may be conducted to assess the patient’s overall health and identify any signs of infection or inflammation.

Treatment for Small Bowel Obstruction in IBD

Conservative Management:

• Non-surgical treatment, such as fasting, intravenous fluids, and bowel rest, is often the initial approach to managing partial obstructions.

Medications:

• Anti-inflammatory medications may be used to manage inflammation and control symptoms.

Nutritional Support:

• Enteral or parenteral nutrition may be necessary if oral intake is compromised.

Surgical Intervention:

• Severe or recurring obstructions may require surgical treatment to remove the affected segment of the bowel, repair fistulas, or address other complications.

When to Consult a Doctor

Patients with IBD should consult a doctor if they experience symptoms of small bowel obstruction, including severe abdominal pain, vomiting, and changes in bowel habits.

Prevention

Preventive measures for small bowel obstruction in IBD patients include:

• Regular follow-up with a healthcare provider to monitor the condition.
• Adherence to prescribed medications to control inflammation.
• Timely management of complications, such as fistulas.

By addressing IBD symptoms and complications proactively, individuals can reduce the risk of small bowel obstructions and maintain a better quality of life.

Conclusion:

Acute SBO: Acute SBO caused by inflammation in Crohn’s disease is more likely to respond to medical treatment.

However, about 75% of people with acute Crohn’s stricture will eventually need some type of intervention, either endoscopic or surgical.

Chronic SBO: Chronic SBO in Crohn’s disease is caused by scarring and narrowing of the bowel.

There is no medication to specifically target this type of SBO, so surgery is often needed