What Is the ICD-10 Ulcerative Colitis Code?

Content reviewed by Ann Dietrich, MD, FAAP, FACEP.  

What is ulcerative colitis? 

Ulcerative colitis is a chronic idiopathic inflammatory condition of the colon characterized by inflammation of the mucosa and submucosa and ulceration of the colon's inner lining.  

It usually begins in the rectum and then progresses throughout the colon and causes  persistent diarrhea, abdominal pain, and rectal bleeding. Unlike Crohn's disease, which can affect any part of the gastrointestinal tract, ulcerative colitis is confined to the colon. 

Symptoms of ulcerative colitis 

Symptoms include: 

• Frequent diarrhea, often with blood or pus 
• Abdominal pain and cramping 
• Urgency to defecate 
• Weight loss and fatigue 
• Fever 
• Anemia

Causes and risk factors 

The exact cause of ulcerative colitis is unknown, but it is believed to involve an abnormal immune response. Genetic factors, environmental triggers, and an imbalance in gut bacteria are also thought to play roles. It typically develops between the ages of 15 and 30, with a smaller peak in incidence between 50 and 70. 

Complications from ulcerative colitis 

Healthcare providers should monitor patients for the following conditions: 

• Leak from anastomosis 
• Pelvic abscess 
• Enterocutaneous fistulas 
• Incontinence 
• Toxic  megacolon 
• Colon/rectal cancer 

ICD-10 code for ulcerative colitis 

The ICD-10 (International Classification of Diseases, 10th Revision) codes for ulcerative colitis provide a standardized way to document and bill for this condition accurately. The codes are found under the category K51. 

Common ICD-10 codes for ulcerative colitis include: 

• K51.0: Ulcerative (chronic) pancolitis 
• K51.2: Ulcerative (chronic) proctitis 
• K51.3: Ulcerative (chronic) rectosigmoiditis 
• K51.4: Inflammatory polyps of colon 
• K51.5: Left-sided colitis 
• K51.8: Other ulcerative colitis 
• K51.9: Ulcerative colitis, unspecified 

Criteria for meeting the ulcerative colitis ICD-10 code 

To accurately use the ICD-10 code for ulcerative colitis, the following criteria must be met based on clinical presentation, diagnostic tests, and medical history: 

1. Clinical presentation: The patient should exhibit symptoms consistent with ulcerative colitis, such as persistent diarrhea with blood, abdominal pain, and urgency to defecate. 
2. Laboratory tests: Blood tests typically showing anemia and elevated inflammatory markers (like C-reactive protein and ESR) can support the diagnosis. 
3. Endoscopic examination: Colonoscopy is the definitive diagnostic tool, revealing inflammation, ulceration, and may show  pseudopolyps in the colon. Biopsies taken during the procedure can confirm the diagnosis. 
4. Imaging studies: Imaging techniques such as CT or MRI may be used to assess the extent and severity of the inflammation and rule out other conditions. 
5. Exclusion of other conditions: Other potential causes of the symptoms, such as infections, Crohn's disease, and irritable bowel syndrome, should be ruled out to ensure an accurate diagnosis. 

Importance of accurate ICD-10 coding for ulcerative colitis 

Accurate coding of ulcerative colitis is crucial for several reasons: 

Patient care: Accurate documentation helps in the formulation of effective treatment plans and facilitates communication among healthcare providers. 

Data collection and research: Proper coding contributes to the collection of reliable data for epidemiological studies, helping improve understanding and management of ulcerative colitis. 

Billing and reimbursement: Correct use of ICD-10 codes ensures appropriate billing and reimbursement from insurance companies and government programs.