Previous gastroenteritis may be associated with later risk for IBD

In this Swedish case-control study, any previous GI infection and previous bacterial, parasitic, and viral GI infection were associated with higher risk for inflammatory bowel disease (IBD) versus controls.

Patients with gastroenteritis may be at higher risk for later Crohn's disease or ulcerative colitis, according to a recent study.

Researchers conducted a case-control study by using data from the Swedish National Patient Register to match patients with inflammatory bowel disease (IBD) and people in the general population. Each case-patient was matched with up to 10 randomly selected controls by sex, year of birth, and place of residence. Reported episodes of gastroenteritis and the associated pathogen were determined, and odds ratios (ORs) for IBD associated with enteric infection were calculated. The study results were published by Clinical Gastroenterology and Hepatology on Oct. 30.

The study included 44,214 patients with IBD (26,450 with ulcerative colitis, 13,387 with Crohn's disease, and 4,377 with unclassified IBD) and 436,507 controls. A little over half of those included were men (51.2%), and median age at IBD diagnosis was 39 years. Overall, 3,105 (7.0%) of patients with IBD had previously had gastroenteritis (1,672 of those with ulcerative colitis, 1,050 of those with Crohn's disease, and 383 of those with unclassified IBD) versus 17,685 controls (4.1%). Most patients in both the IBD and control groups who had a previous gastroenteritis episode were hospitalized for it (77.6% and 83.5%, respectively), and most had only one episode (76.7% and 79.3%, respectively).

After adjustment for previous bowel surgery, other autoimmune disease, or first-degree relative with IBD, the researchers found that any episode of GI infection (adjusted OR, 1.64; 95% CI, 1.57 to 1.71), any bacterial GI infection (adjusted OR, 2.02; 95% CI, 1.82 to 2.24), any parasitic GI infection (adjusted OR, 1.55; 95% CI, 1.03 to 2.33), and any viral GI infection (adjusted OR, 1.55; 95% CI, 1.34 to 1.79) were associated with higher risk for IBD versus controls. Increased odds for IBD were associated with increased numbers of gastroenteritis episodes. In addition, a significant association was seen between a previous gastroenteritis episode and risk for IBD after more than 10 years (adjusted OR, 1.26; 95% CI, 1.19 to 1.33). Patients with ulcerative colitis were more likely than controls to have had Salmonella, Escherichia coli, Campylobacter, or Clostridium difficile infection, while patients with Crohn's disease were more likely to have had Salmonella, Campylobacter, Yersinia enterocolitica, C. difficile, amoeba, or norovirus infection compared with controls.

The authors noted that most gastroenteritis cases occurred in inpatients and that limited or no data were available on antimicrobial prescribing patterns, smoking history, previous antibiotic exposure, or disease severity. They also cautioned that the study had little power to assess IBD risk with specific pathogens, among other limitations, and that their findings should be interpreted with caution. However, they concluded that in their study population, previous exposure to a GI infection was associated with later development of IBD.

“Although we cannot formally exclude surveillance, misclassification or detection bias, this association varied by type of pathogen, persisted over time, and increased with repeated episodes of gastroenteritis, consistent with growing translational data on dysbiotic triggers in IBD,” they wrote.