Ulcerative colitis (UC) and Crohn's disease (CD) are inflammatory bowel diseases (IBD) which, by definition, affect the gastrointestinal tract. However, UC and CD are associated with various complications affecting other organs in the body. These "extra-intestinal" affects are immune-mediated and typically affect the joints, skin, eyes, liver and/or gallbladder. Other possible complications of IBD, include colorectal cancer and other malignancies.
Joints and bones
Various different bone and joint disorders have been associated with IBD. The overall prevalence of bone and joint disorders related to IBD is about 30 percent. Arthritis is the most common disorder to occur. It may affect the spine or low back/hips (sacroiliac joints) and occurs more frequently in men. Arthritis may also affect the joints of the extremities and can be acute with only a few joints involved, typically following disease activity (Type I). In other words, when someone has a flare of UC or CD with sudden pain of a few joints, it is more likely to be Type I arthritis and will improve with control of the IBD flare.
Alternatively, arthritis can be chronic in nature and affect the joints of the hands more than the limbs (Type II). Type II does not typically parallel the activity of the intestinal disease.
Osteopenia and osteoporosis are very common in those with IBD, occurring in about 50-70 percent of individuals with IBD. This risk is likely due to many factors, including use of steroids to treat uncontrolled IBD symptoms, abnormal absorption of calcium and vitamin D as a result of damage to the intestinal lining, increased pro-bone resorption factors as a result of the activated immune response in IBD, malnutrition, and low body-mass index. It is important that your doctor monitors your bone density and calcium/vitamin D levels.
There are numerous skin lesions and disorders associated with IBD. The two most common are called erythema nodosum and pyoderma gangrenosum. Pyoderma gangrenosum is an ulcerative condition that starts out with small red or pus-like lesions. These lesions continue to grow into a large ulcer with irregular borders and exhibits a phenomenon called pathergy, or worsening of the lesion with trauma. These lesions typically occur on the legs, but can be found on any body surface, even at stoma sites after bowel surgery for IBD. These lesions typically do not parallel IBD activity. Erythema nodosum, on the other hand, does parallel the intestinal disease activity in CD and UC. Erythema nodosum is the most common skin manifestation of IBD, occurring in about 3 to 10 percent of those with UC and 5 to 15 percent of those with CD. These lesions are raised, tender, red/violet in color, and under the skin. They occur most often on the shins or other surfaces of the extremities. Treating the underlying IBD flare will usually treat these lesions.
There are several disorders of the eye related to IBD. A few in particular warrant urgent evaluation by an ophthalmologist. Warning signs for urgent evaluation include reduced vision or clarity, foreign body sensation, inability to open the eye, a fixed pupil, headache with nausea or vomiting, opaque cornea, and certain patterns of redness. Disorders requiring urgent evaluation include keratitis, uveitis, scleritis, and closed angle glaucoma. Some eye disorders, such as episcleritis, may not be as urgent, however, the symptoms may mimic or be very similar to those of more urgent disorders. Therefore, if you are experiencing any eye symptoms, it is important to discuss these with your gastroenterologist to determine whether further specialized evaluation is needed. In most cases, a referral to an ophthalmologist will be made.
Liver and gallbladder
The most common and most important condition associated with IBD affecting the liver and gallbladder is primary sclerosing cholangitis (PSC). This is characterized by inflammation of the bile ducts throughout the liver resulting in significant scarring of the ducts and blockage of bile flow through these ducts. Most patients with IBD-associated PSC have UC, rather than CD. Those with PSC may present with fatigue, yellowing of the skin, and skin itching. On exam, they may have an enlarged liver or spleen. The course of PSC does not parallel intestinal disease activity. Other less common disorders of the liver and gallbladder that are associated with IBD include autoimmune hepatitis (again usually in those with UC) and gallstones (more specifically seen in those with CD).
Those with UC (and possibly with Crohn's colitis) are at increased risk colorectal cancer. In patients with UC, the relative risk for colorectal cancer is two to eight times higher than the general population. The extent of colitis and duration of disease are the most important risk factors. Other risk factors include severity of inflammation, presence of pseudopolyps, and presence of PSC. Surveillance colonoscopies at regular intervals are recommended to monitor for polyps of precancerous changes. Colonoscopy exams can help detect early, curable colorectal cancers. PSC is a risk factor for cholangiocarcinoma (cancer of the gallbladder/biliary tree), and therefore, those with UC are at increased risk for this type of cancer. Those with CD involving the small intestines are at slightly increased risk for cancer of the small intestines.
It is important to discuss any and all types of symptoms you may be experiencing with your gastroenterologist. Some of these symptoms could be associated with your IBD. Also, it is important to undergo surveillance testing as indicated to monitor for some of these IBD-related conditions.