More antibiotic prescriptions, higher IBS odds in young adults

Clinical takeaway: Avoid unnecessary antibiotic prescriptions, particularly repeated courses in children and adolescents. These findings suggest a possible longer-term gastrointestinal consequence of exposure, but do not establish causality or justify withholding antibiotics when indicated.

Antibiotics can alter the gut microbiome, raising questions about whether repeated exposure could contribute to irritable bowel syndrome (IBS). Previous studies have suggested a link, but evidence connecting childhood use with adult IBS has been inconsistent and often relied on recalled antibiotic use.

A study presented at UEG Week 2026 used prescription records to examine this relationship in 2,853 participants from a Swedish birth cohort. Researchers tracked prescriptions from ages 9–11 through one year before IBS assessment at age 24, when 10% of participants had IBS.

After adjustment for sex and family socioeconomic status, participants prescribed antibiotics had 1.5 times the odds of IBS compared with those receiving none. The odds increased with prescription count: 1.3 times with one or two prescriptions, 1.6 times with three to five, and 1.7 times with six or more.

The findings reinforce antibiotic stewardship, but cannot determine whether antibiotics preceded IBS onset or whether infections and other factors contributed to the association. Microbiome disruption is a possible explanation. The study did not test that mechanism.

“Antibiotics remain an important and sometimes essential treatment for bacterial infections, and our findings should not discourage their use when they are needed,” said lead author Jessica Sjölund, MD, PhD, of Sahlgrenska University Hospital and the University of Gothenburg. “Rather, they highlight the possibility of longer-term effects from repeated exposure and add to the reasons for avoiding unnecessary antibiotic prescribing.”

Source: Sjölund J, et al. (2026 Oct 19). UEG Week 2026. Antibiotic use from childhood and risk of adult irritable bowel syndrome: findings from a prospective birth cohort