Small Intestine Enteropathies, Noninfectious

• • Damage to the small intestinal mucosa due to NSAIDs or radiation exposure

  • Ensuing inflammation can result in mucosal ulceration, diarrhea, and GI bleeding

  • Late complications of NSAID and radiation enteropathy include stricture and obstruction

Epidemiology

NSAID Enteropathy

• • NSAIDs increase intestinal permeability, leading to mucosal inflammation

  • Enteropathy, with subclinical intestinal inflammation and occult blood loss, develops in 70% of patients who have taken NSAIDs for > 6 months

  • Mucosal ulceration or transmural inflammation and fibrosis with circumferential strictures develop in < 1%

Radiation Enteropathy

• • Injury to blood vessels in the bowel wall leads to endothelial proliferation and fibrosis that obliterates the vessel lumen producing chronic intestinal ischemia

  • Incidence of bowel injury is dose-related

  • -5% after 4500 cGy

    -30% after 6000 cGy

  • Fixed loops of small bowel in the radiation field increases the risk of intestinal complications

Symptoms and Signs

• • Nausea and vomiting

  • Abdominal pain

  • GI bleeding

  • Diarrhea, which may be bloody

  • Abdominal tenderness

Laboratory Findings

• • Anemia

Imaging Findings

• • Abdominal x-ray

  • -If obstruction is present, dilated loops of bowel proximal to the obstruction with air-fluid levels and thickened bowel wall

    -Free air suggests perforation

  • Upper GI contrast radiography: Narrowed, stenotic segment of bowel

  • CT scan

  • -Dilated bowel with bowel wall edema proximal to the obstruction with narrowed, stenotic bowel at the site of obstruction

    -Free air suggests perforation

  • Endoscopy

  • -Inflamed mucosa

    -May identify the strictured segment of bowel

• • Strictures, either inflammatory (NSAID enteropathy) or ischemic (radiation enteropathy) can present as a late complication and result in obstruction or perforation

Rule Out

• • Crohn disease

  • Ischemia

  • TB

  • Lymphoma

  • Primary or recurrent carcinoma

• • Abdominal x-ray

  • GI contrast radiography

  • CT scan

  • Endoscopy

When to Admit

• • Obstruction

  • Perforation

  • Bleeding

NSAID Enteropathy

• • Discontinue drug

Radiation Enteropathy

• • Symptoms may appear as early as 1 month or as late as 30 years after completion of therapy

Surgery

• • Resection indicated for complications

Indications

• • Obstruction

  • Perforation

  • Bleeding

  • Abscess

  • Fistula

Complications

• • Obstruction

  • Perforation

  • Bleeding

  • Abscess

Prognosis

• • Good for NSAID enteropathy after medication is discontinued

  • Symptoms are usually minor and transient with radiation enteropathy

References