Description

• Idiopathic inflammatory disease of the colonic mucosa that can affect any section of the colon from the rectum to the cecum
• >95% of patients have rectal involvement, with 50% of cases limited to rectum and sigmoid.
• 20% have pancolitis.

Epidemiology

• US: 9–12 new cases/100,000 persons/year
• Predominant age: 15–35 years; 2nd and smaller peak in the 7th decade
• Predominant sex: Female > Male (slight)

• Similar to general population; 1 study showed 30% with inactive disease at onset of pregnancy relapsed.
• Treatment with sulfasalazine does not seem to affect pregnancy outcome.
• Patients should delay pregnancy until disease is inactive.

Risk Factors

• Better sanitation, indoor work environments, and fatty foods increase risk.
• NSAIDs can activate disease.
• Appendectomy is protective against later development of disease.
• Negative association with smoking: Relative risk of smokers is 40% of nonsmokers.

• Family history in 5–10% in population surveys and 20–30% in referral-based studies
• More common in the Jewish population

General Prevention

• Patients with long-term disease who do not have colectomy are at increased risk for colon cancer.
• Aspirin (≥300 mg/d) and ursodeoxycholic acid (10 mg/kg) have been shown to be preventive.

Pediatric Considerations
Breastfeeding may be protective for pediatric inflammatory bowel disease (IBD).

Etiology

Unknown; hypotheses include allergy to dietary components and abnormal immune responses to bacterial or “self” antigens; final outcome is mucosal inflammation secondary to immune cell infiltration.

Commonly Associated Conditions

• Extracolonic manifestations in 10–15%
• Arthritic conditions, including large joint arthritis, sacroiliitis, and ankylosing spondylitis
• Pyoderma gangrenosum
• Episcleritis and uveitis
• Sclerosing cholangitis
• Asymptomatic fatty liver (common); occasional hepatomegaly
• Primary sclerosing cholangitis: 1–4%
• Cirrhosis of liver: 1–5%
• Bile duct carcinoma
• Thromboembolic disease: 1–6%