Introduction
Ulcerative colitis (UC) is a chronic inflammatory bowel disease causing continuous inflammation and ulcers in the colon and rectum. Symptoms include bloody diarrhea, urgency, and abdominal cramps that flare and remit over time.
It differs from Crohn disease by affecting only the colon and involving the mucosal layer continuously from rectum proximally. Cause involves immune dysregulation in genetically susceptible people.
Treatment uses aminosalicylates, steroids, immunomodulators, and biologics to induce and maintain remission. Surgery (colectomy) cures colitis but requires ileostomy or pouch in selected cases.
This page explains UC in plain language.
Overview
Onset often in young adulthood. Long-standing extensive colitis raises colon cancer screening needs. Extra-intestinal manifestations include joint pain, skin lesions, and eye inflammation.
- Chronic inflammatory disease of colon lining
- Bloody diarrhea and urgency hallmark
- Continuous inflammation from rectum upward
- Treated with anti-inflammatory and biologic drugs
- Colon cancer surveillance in long disease
- Colectomy curative for colon but life-changing
What happens in the body
Mucosal immune system overreacts to gut microbiota in context of barrier defects and genetic variants. Neutrophil infiltration produces crypt abscesses and ulceration.
Flares may follow infections, NSAIDs, or unknown triggers; stress does not cause UC but may worsen symptoms.
- Limited to colon—no skip lesions unlike Crohn
- Pan-colitis increases cancer risk most
- Primary sclerosing cholangitis association in subset
- TNF-driven inflammation target of biologics
Signs and symptoms
Typical bowel and systemic signs:
- Bloody diarrhea with mucus
- Urgency and tenesmus
- Lower abdominal cramping
- Weight loss in moderate-severe flares
- Fatigue and anemia from blood loss
- Fever in severe colitis
- Joint pains or eye redness in extraintestinal manifestations
Causes and risk factors
Contributing factors:
- Immune dysregulation with genetic susceptibility (NOD2, HLA, many loci)
- Altered gut microbiome interactions
- Not caused by specific food alone though diet affects symptoms
- Family history increases risk
- Smoking oddly protective for UC though harmful overall
- Appendectomy associated with lower UC risk in some studies
Diagnosis and evaluation
Diagnostic workup:
- Colonoscopy with biopsies showing continuous colitis from rectum
- Exclude infection: C diff, CMV in severe cases
- Stool calprotectin elevated in active inflammation
- CBC, CRP, iron studies for anemia and activity
- Differentiate Crohn, ischemic colitis, microscopic colitis
- Imaging when severe toxicity or perforation concern
Treatment and management
Induction and maintenance:
- 5-ASA enemas or oral mesalamine for mild distal disease
- Oral or topical steroids for moderate flares
- Azathioprine or methotrexate for steroid-sparing
- Anti-TNF, vedolizumab, ustekinumab, JAK inhibitors for moderate-severe disease
- Hospitalization IV steroids or infliximab for acute severe colitis
- Colectomy with ileal pouch-anal anastomosis or permanent ileostomy when refractory or dysplasia
- Iron replacement, nutrition support, psychology support
- Colonoscopy surveillance every 1-3 years after 8-10 years pancolitis
Prevention, self-care, and lifestyle
Not every condition is fully preventable, but the steps below may lower risk or recurrence:
- Cannot prevent initial UC onset
- Maintain remission with adherence to maintenance meds
- Avoid NSAIDs when possible
- Vaccinate before immunosuppression per guidelines
- Report flare symptoms early to adjust therapy
Possible complications
Delay, missed care, or unsafe self-medication can raise the chance of complications in some cases:
- Toxic megacolon and perforation in severe flare
- Colon cancer in long-standing disease
- Primary sclerosing cholangitis needing liver monitoring
- Osteoporosis from steroids
- Clostridium difficile superinfection
- Growth delay in pediatric UC
When to see a doctor or seek emergency care
Seek prompt medical advice or emergency care if any of the following apply—it is safer not to wait and see:
- Increased stool frequency with blood
- Severe abdominal distension and fever
- Unable to keep down fluids during flare
- New jaundice or itching with UC (PSC concern)
- Routine colon cancer surveillance overdue
Living with the condition
Many achieve long remissions on maintenance therapy. Diet personalization (low residue during flare) helps symptoms though no universal UC diet exists. Support groups address stigma of bowel disease.
Frequently asked questions
Is UC the same as Crohn?
No. UC affects colon only continuously; Crohn can affect any GI tract segment with skip areas and deeper inflammation.
Do I need surgery?
Many never need surgery; it is considered for medication failure, dysplasia, or complications.
Can diet cure UC?
No cure by diet alone, but certain foods may trigger symptoms individually.
Is it contagious?
No. It is autoimmune-inflammatory, not infectious.
Important caution
This article is general health education in English. It is not personal medical advice.
Severe colitis with fever and distension is a medical emergency.
IBD management requires gastroenterology specialist care.