Ulcerative Colitis Overview

Ulcerative colitis (UC) is a chronic form of inflammatory bowel disease that inflames the inner lining of the colon and rectum. Inflammation starts in the rectum and spreads upward in a continuous pattern. Many people cycle between flares and remission. Modern care aims for steroid‑free remission and healing of the colon lining using medicines, monitoring, and when needed, curative surgery. (niddk.nih.gov)

Key Takeaways

• UC affects the colon’s inner lining, always involves the rectum, and spreads continuously rather than in “skip” patches. (journals.lww.com)

• Extent is described by Montreal E1–E3: proctitis, left‑sided colitis, and extensive colitis. Extent guides topical versus systemic therapy choices. (academic.oup.com)

• Most people have a relapsing‑remitting course. The goal is steroid‑free remission using a treat‑to‑target plan that tracks symptoms, stool markers, and endoscopic healing. (pubmed.ncbi.nlm.nih.gov)

• Mild to moderate UC often responds to 5‑aminosalicylates (5‑ASA), including rectal forms for distal disease. (gastro.org)

• Moderate to severe or steroid‑dependent UC usually needs advanced therapies such as biologics, JAK inhibitors, or S1P modulators. (gastro.org)

• A minority require hospitalization for acute severe UC or surgery. Colectomy rates have fallen in many modern cohorts. (gastro.org)

What UC Is and Where It Occurs

UC is an immune‑mediated disease confined to the large intestine. Inflammation targets the mucosa, the innermost lining. It begins in the rectum and extends upward in a continuous stretch, which helps distinguish it from Crohn’s disease. This pattern explains why rectal therapies can be very effective for distal disease. (journals.lww.com)

Clinicians describe how far UC goes using the Montreal system:
- E1, proctitis, limited to the rectum.
- E2, left‑sided colitis, up to the splenic flexure.
- E3, extensive colitis, beyond the splenic flexure. (academic.oup.com)

Typical Disease Course

UC often follows a relapsing‑remitting pattern. Periods of flare alternate with weeks to years of remission. Some people experience extension of disease over time, moving from proctitis to more proximal involvement. A small share develop acute severe colitis that needs hospital care. Overall, the long‑term need for colectomy has decreased in the modern treatment era, with many cohorts reporting roughly 5 to 10 percent at 10 years, though rates vary by region and disease extent. (niddk.nih.gov)

How UC Is Managed

Treatment is organized by extent and severity, with separate plans for starting remission (induction) and keeping remission (maintenance). Avoiding repeated or long steroid courses is a key principle. (journals.lww.com)

• Mild to moderate disease

• Oral 5‑ASA for left‑sided or extensive colitis, often combined with rectal 5‑ASA. Rectal suppositories or enemas are first‑line for proctitis and proctosigmoiditis. Budesonide MMX can help selected patients. (gastro.org)

• Moderate to severe disease, steroid‑dependent disease, or frequent relapses

• Advanced therapies are used early. Options include anti‑TNF agents, anti‑integrin therapy, interleukin‑12/23 or interleukin‑23 inhibitors, JAK inhibitors, and S1P receptor modulators. Choice depends on prior drug exposure, speed needed, safety profile, and patient preferences. (gastro.org)

• Acute Severe Ulcerative Colitis (ASUC)

• In hospital, first‑line care is intravenous steroids. If there is no response, rescue therapy with infliximab or cyclosporine is recommended, with early surgical input. (gastro.org)

• Surgery

• Colectomy cures colitis because UC is limited to the colon. It is used for medically refractory disease, dysplasia or cancer, or complications like severe bleeding. Restorative surgery with an ileal pouch‑anal anastomosis (J‑pouch) is common. (academic.oup.com)

Medication classes at a glance

Guideline positioning favors early use of higher‑efficacy advanced therapies in moderate to severe disease, rather than slow step‑up after failure. (gastro.org)

Treat‑to‑Target and Monitoring

Modern care sets clear targets. Short‑term goals are symptom relief and normalization of blood and stool markers, such as fecal calprotectin. Long‑term goals include clinical remission and endoscopic healing. Teams use regular check‑ins, stool calprotectin testing, and periodic flexible sigmoidoscopy or colonoscopy to confirm healing and adjust therapy. (pubmed.ncbi.nlm.nih.gov)

Cancer Surveillance

Long‑standing colitis that extends beyond the rectum increases colorectal cancer risk. Most groups begin IBD‑specific surveillance colonoscopy 8 years after symptom onset for patients with colonic disease, then use risk‑based intervals: about every 1 year for high risk, every 2 to 3 years for intermediate risk, and every 5 years for low risk. People with disease limited to the rectum typically follow general population screening. Primary sclerosing cholangitis requires annual surveillance from diagnosis. (academic.oup.com)

FAQs

Does UC skip areas of the colon

No. UC starts in the rectum and extends upward in a continuous stretch. Skip areas suggest another diagnosis or a special situation. (journals.lww.com)

Is surgery a cure for UC

Yes for colitis. Removing the colon eliminates UC inflammation, although pouch‑related problems can occur after a J‑pouch. Surgery is reserved for specific indications. (academic.oup.com)

What makes someone “moderate to severe”

Severity reflects symptoms, bleeding, lab markers, and endoscopic findings. Frequent steroid need, poor response to 5‑ASA, or extensive disease usually push treatment toward advanced therapies. (journals.lww.com)

How is progress tracked between scopes

Teams often use fecal calprotectin to signal inflammation changes. Rising values can prompt earlier reassessment. (journals.lww.com)