Some of the associated complications of severe Crohn's disease include: 

• perforated bowel;
• stricture;
• fistula;
• abscesses; and
• malabsorption or malnutrition. 

Crohn's may cause or contribute to complications outside of the GI tract including an increased risk of: 

• kidney stones;
• osteoporosis;
• skin ulcers;
• swelling; and
• joint pain. 

Crohn's patients are also at a slightly greater risk for several other diseases, such as colon cancer and primary sclerosing cholangitis (PSC), a liver disease.