What is the most likely long-term complication of ulcerative colitis?

The most likely long-term complication of ulcerative colitis is colon cancer. Individuals with ulcerative colitis, especially those with pancolitis (involvement of the entire colon), have an increased risk of developing colorectal cancer over time. The risk increases significantly after 8 to 10 years of having the disease, due to the dysplastic changes in the colonic mucosa that can occur as a result of ongoing inflammation and repair processes associated with ulcerative colitis.

Regular surveillance colonoscopy is recommended for patients with ulcerative colitis to screen for dysplasia and early cancer, starting typically around 8 years after diagnosis. This is crucial because colorectal cancer arising from ulcerative colitis often has a different pathogenesis than typical cancer, being linked directly to the precancerous dysplastic changes induced by the chronic inflammation.

In contrast, while options such as short bowel syndrome, intestinal obstruction, and increased B12 absorption can have associations with gastrointestinal diseases, they are not recognized as long-term complications specific to ulcerative colitis. Short bowel syndrome is more related to extensive surgical resections or conditions that severely impact intestinal length and absorption. Intestinal obstruction, while possible, is less chronically problematic compared to cancer risk. Increased B12 absorption is not