Ulcerative colitis is typically viewed as a digestive tract condition. However, a significant study conducted across the United States indicates that individuals with this illness might also be at higher risk for a type of lung disease compared to those with Crohn’s disease.
This discovery emphasizes how illnesses originating in the gut can sometimes impact the entire body.
Ulcerative colitis and Crohn’s disease are the primary forms of inflammatory bowel disease, or IBD. These are chronic conditions where the immune system triggers recurring inflammation throughout the digestive system. Symptoms often improve temporarily but tend to flare up again during active phases of the disease.
Ulcerative colitis primarily affects the inner lining of the colon and rectum. Crohn’s disease, on the other hand, can invade deeper layers of the bowel and may appear in different sections of the digestive tract. Both conditions can lead to diarrhea, abdominal pain, bleeding, fatigue, and weight loss.
But IBD is more than just a gut issue. Some patients experience painful joints, skin conditions, eye inflammation, or liver problems. Researchers have also identified lung issues among people with IBD, although the extent of this risk and who is most vulnerable remain unclear.
Scientists led by Dr. Sneh Parekh from the University of Florida College of Medicine in Jacksonville focused on a specific lung complication called interstitial lung disease (ILD). ILD affects the tissue supporting the tiny air sacs in the lungs. Inflammation or scarring here can reduce lung flexibility and hinder oxygen transfer into the blood.
Symptoms of ILD can include a persistent dry cough or shortness of breath during activities once performed easily. Some individuals initially experience only mild symptoms, and because breathing issues are common to many illnesses, lung problems may go unnoticed or be diagnosed late.
The research team reviewed medical records from 8,865 patients with IBD treated at two major specialty centers in the southeastern U.S. between 2012 and 2022. Their goal was to determine how often ILD appeared and whether its occurrence differed between Crohn’s disease and ulcerative colitis.
They discovered that 4.6% of these patients had both IBD and ILD. Notably, ILD was more prevalent among patients with ulcerative colitis than among those with Crohn’s disease. Demographic factors like age and gender were similar across both groups with lung involvement.
The patients with both bowel and lung issues tended to be older and used hospital services more frequently than those with IBD alone. They visited emergency rooms and required hospital stays more often, indicating a possibly more complex health condition when both diseases coexist.
Use of corticosteroids was also higher among these patients. While steroids can be effective for quickly reducing gut inflammation during flares, long-term use is often avoided due to risks like weakened bones, infections, and other side effects. Interestingly, fewer patients with ILD were on mesalamine, a common IBD medication.
The study also noted a higher occurrence of additional health conditions among minority groups with both IBD and ILD compared to white patients. This finding raises important questions about health disparities, treatment access, and overall care that require further exploration.
So, what might link bowel disease to lung problems? One possibility is that the abnormal immune response causing gut inflammation could also target lung tissue. Since the digestive tract and airways share some biological features, researchers believe there’s a direct connection, though it’s not fully understood yet.
Other explanations include medication side effects or unrelated lung diseases. Some drugs used for IBD might occasionally impact the lungs, and infections or other respiratory illnesses can produce similar symptoms. This underscores the importance of thorough evaluation when respiratory issues arise in IBD patients rather than assuming they are directly related.
This research was published online on July 24 in Crohn’s & Colitis 360. The authors suggest that recognizing lung involvement earlier could help reduce healthcare burdens for those with IBD. Since resources for screening all patients may be limited, they recommend special focus on ulcerative colitis patients who might be at higher risk.
These findings are significant because the study analyzed a large set of real-world clinical data spanning a decade. The notable difference between ulcerative colitis and Crohn’s disease provides a valuable basis for future research to delve deeper into these associations.
However, the study doesn’t prove that ulcerative colitis causes ILD. Because it reviewed existing patient records rather than conducting randomized trials, other factors could partly explain the link. Additionally, patients treated at specialized centers might have more severe disease than the general IBD population.
Further research is necessary to identify which patients are truly at highest risk and whether routine lung screening improves health outcomes. It’s also important to differentiate lung issues caused directly by IBD from those resulting from medications, infections, smoking, or other conditions. Such information would aid doctors in avoiding unnecessary tests and diagnosing serious problems earlier.
For now, these findings encourage a broader perspective on IBD. Patients with ulcerative colitis or Crohn’s should not assume every cough is related to their intestinal disease, but persistent breathlessness or a chronic dry cough warrants medical evaluation. Recognizing that IBD can impact organs beyond the gut may lead to earlier detection of potentially serious complications.
Source: University of Florida.

