When diarrhea and bloody stools persist, a disease must be suspected.

That is ulcerative colitis, a chronic, intractable disease characterized by inflammation and ulcers that develop throughout the entire colon mucosa. Recently, the number of patients, particularly among younger individuals, has been increasing rapidly.

"Ulcerative colitis differs from Crohn's disease, a similar inflammatory bowel disease, in the pattern of lesions. Crohn's disease can occur anywhere in the digestive tract, with inflammation spreading not only to the mucosa but also deep into the intestinal layers, forming scattered lesions,” said Professor Lee Won-myung of the Department of Gastroenterology at Soon Chun Hyang University Hospital Bucheon. “In contrast, ulcerative colitis is characterized by lesions appearing continuously throughout the entire colon."

The exact cause of ulcerative colitis remains unknown, but it is understood to result from a combination of genetic factors, immune dysfunction, gut bacterial imbalance, and environmental factors. According to national health insurance statistics, the number of patients in Korea has also increased rapidly, surpassing 40,000 in 2022 and more than quadrupling over the past decade.

Major symptoms include frequent diarrhea, persistent bloody stools, mucus-containing stools, abdominal pain, and occasionally fever. While common enteritis typically improves within days, ulcerative colitis can persist for weeks to months or recur. If diarrhea, bloody stools, or stools containing mucus continue, medical attention is essential. Diagnosis involves distinguishing it from other intestinal diseases by comprehensively evaluating patient symptoms alongside colonoscopy, biopsy, blood/stool tests, and imaging studies.

Treatment for ulcerative colitis varies based on disease severity and extent. First-line therapy uses oral 5-aminosalicylic acid (5-ASA) drugs; steroids or immunomodulators are added if symptoms are severe. Recently, even patients unresponsive to conventional medications are achieving “remission”—a state enabling normal daily life—through advanced therapies like biologics and small-molecule agents, significantly improving their quality of life.

“Ulcerative colitis is a rare, intractable disease that is difficult to cure, but early treatment and management can enable a near-normal life,” Professor Lee said. “The treatment goal is to achieve ‘clinical remission’ by suppressing inflammation and alleviating symptoms, and further, to attain ‘mucosal remission’ where no inflammation is visible on endoscopy, thereby maintaining quality of life and preventing complications.”

If inflammation remains uncontrolled and becomes chronic, complications such as colorectal cancer, intestinal strictures, and toxic megacolon (a life-threatening emergency complication where the colon severely dilates) can occur. Since surgical treatments like total colectomy may be necessary if the disease does not respond to medication or if severe complications arise, early treatment is crucial.

Dietary and lifestyle management also helps control and suppress ulcerative colitis. It is advisable to avoid spicy foods, caffeine, and alcohol while maintaining a balanced diet and staying adequately hydrated. Smoking and stress are also factors that worsen symptoms, necessitating smoking cessation and appropriate stress management.

“Ulcerative colitis often develops in younger individuals, and frequent hospital visits and long-term treatment can place a significant burden on academic or professional life,” Lee said. “While symptoms can be easily confused with irritable bowel syndrome, if diarrhea, bloody stools, or mucus-containing stools recur for several weeks or longer, it is essential to undergo testing. Particular caution is needed if there is a family history of inflammatory bowel disease.”