Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) in which the immune system sustains inflammation and ulcers in the mucosa of the colon and rectum. The inflammation is continuous, begins at the rectum and spreads upward, but affects only the mucosal layer.
This distinguishes UC from Crohn's disease, where the involvement can occur along the entire length of the GI tract, in "segments" and through the full thickness of the wall. The course is undulating: flares alternate with remissions.
Symptoms and complications
The leading complaints are frequent loose stools with blood and mucus, false urges (tenesmus), cramping abdominal pain and urgency of defecation. With extensive inflammation, weakness, weight loss and anemia from blood loss and iron deficiency are added.
Dangerous complications are toxic megacolon and an increased risk of colorectal cancer, which grows with disease duration (estimated at up to 20–30% after several decades of total colitis), so regular endoscopic screening is needed. Extraintestinal manifestations also occur — arthritis and involvement of the eyes and skin.
Diagnosis
The key method is colonoscopy with biopsy: a friable, granular mucosa with loss of the vascular pattern and superficial erosions is seen. Activity and flares are assessed with C-reactive protein, other inflammatory markers and fecal calprotectin.
By extent (the Montreal classification), proctitis, left-sided colitis and total colitis (pancolitis) are distinguished. UC symptoms are sometimes confused with food intolerance or irritable bowel syndrome, but in UC there is objective inflammation and mucosal damage.
Treatment and longevity
The mainstay for mild and moderate forms is 5-aminosalicylic acid drugs (mesalazine); glucocorticoids are added during flares, and for severe and refractory disease — immunosuppressants and biologics (anti-TNF, vedolizumab). Removal of the colon (colectomy) radically cures UC.
Chronic bowel inflammation is linked to the state of the gut microbiome and, like other autoimmune diseases (for example, rheumatoid arthritis), increases the systemic inflammatory burden. Controlling inflammation and correcting anemia and deficiencies are important for quality of life and longevity.
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Calculators where Ulcerative colitis is used directly:
Frequently asked questions
How does ulcerative colitis differ from Crohn's disease?
UC affects only the colon and rectum; the inflammation is continuous and limited to the mucosa. Crohn's disease can involve any part of the GI tract, runs in "segments" and through the full thickness of the wall, and more often produces fistulas.
Does ulcerative colitis raise the risk of bowel cancer?
Yes; with long-standing and extensive inflammation the risk of colorectal cancer grows with disease duration, so regular colonoscopy and control of inflammation are needed. Sustained remission lowers this risk.