Ulcerative colitis is an inflammatory bowel disease that leads to inflammation and ulcers in the digestive tract's mucosa; it starts in the rectum and potentially spreads to the colon. Symptoms typically arise between the ages of 15 and 30, and studies show a second peak later in life, after the age of 50 or older (ages 70-79).

The main symptom of ulcerative colitis is bloody diarrhea, which may occur with or without mucus. Other symptoms include an increased urge to defecate, abdominal pain, weight loss, fever, anemia, and fatigue, with periods of remission and relapse.

Ulcerative colitis is diagnosed by ruling out other conditions through a physical exam, blood tests, and stool tests. A biopsy may be performed during a colonoscopy or sigmoidoscopy to confirm the diagnosis.

Ulcerative colitis is managed with medications such as 5-aminosalicylates as the first-line treatment, followed by immunosuppressants or corticosteroids if necessary. In severe cases, surgical options like restorative proctocolectomy ileal pouch-anal anastomosis (RPC-IPAA) may be performed to remove the large intestine and rectum.

Vitamin D has been shown to reduce inflammatory biomarkers and improve intestinal barrier function in ulcerative colitis when used alongside 5-ASA medications, and curcumin may aid in achieving remission but requires further study. Additionally, there is evidence supporting the use of probiotics, prebiotics, and synbiotics for remission and inflammation reduction, with recommendations for supplementation of nutrients like iron, vitamin D, and folic acid for people with deficiencies.

Restrictive diets do not show benefits for people with ulcerative colitis and may lead to nutritional deficiencies. Although the low-FODMAP diet may alleviate some symptoms of inflammatory bowel disease, it does not enhance stool consistency or decrease mucosal inflammation.

Emerging evidence suggests that fecal microbiota transplants may help achieve remission in ulcerative colitis, whereas helminth therapy has shown conflicting results. Additionally, traditional Chinese medicine treatments like moxibustion and acupuncture have been studied, but their effectiveness is uncertain due to poor-quality research.

The specific cause of ulcerative colitis (UC) is unknown, but it is believed to involve a dysfunction in the immune system that leads to damage in the digestive tract. Factors such as genetics, lifestyle, and the gut microbiome also contribute to the development of UC.