Study finds an association, not a cause
Antibiotic prescriptions received from childhood through early adulthood were associated with higher odds of irritable bowel syndrome at age 24 in a Swedish population-based study presented at UEG Week 2026. The association became stronger as the number of recorded prescriptions increased.
The finding does not establish that antibiotics cause IBS. It identifies a relationship in observational data, and the researchers accounted for sex and family socioeconomic status in their analysis. Other factors could still contribute to both the likelihood of receiving antibiotics and the later development of digestive symptoms. But the study adds objectively recorded prescription data to a question that has often relied on people remembering their past medicine use.
IBS is a common digestive disorder characterized by abdominal pain and changes in bowel habits. The report says it affects more than 60 million people across Europe. Previous research has suggested a possible connection between antibiotic exposure and IBS, but evidence about exposure in childhood and IBS in adulthood has been inconsistent.
Following a Swedish birth cohort
Researchers examined 2,853 participants in the Swedish BAMSE birth cohort. They used antibiotic prescription records from the Swedish Prescribed Drug Register beginning in 2005, when participants were 9 to 11 years old. Prescriptions were tracked until one year before IBS was assessed at age 24.
That design addresses a practical weakness in studies based on recall. A person asked at age 24 to recount treatments received years earlier may not remember every prescription, the timing of treatment or the antibiotic used. Register data cannot answer every clinical question, but it can provide a more consistent record of prescriptions filled over the study period.
At age 24, 10.0% of the cohort had IBS. Of the participants with IBS, 79.4% were female. Antibiotic use was more common among people with IBS than among those without it: 87.8% of the IBS group had received antibiotics during the study period, compared with 80.2% of participants who did not have IBS.
Prescription counts tracked with increasing odds
After adjustment for sex and family socioeconomic status, participants who had received antibiotics had 1.5 times the odds of IBS compared with participants who had not received them. The reported 95% confidence interval was 1.0 to 2.2.
The pattern was more pronounced when the researchers examined the number of prescriptions. Compared with participants who received no antibiotics, those with one or two prescriptions had 1.3 times the odds of IBS, with a 95% confidence interval of 0.9 to 2.0. The estimate rose to 1.6 for those with three to five prescriptions, with a confidence interval of 1.0 to 2.4.
For participants with six or more prescriptions, the odds estimate was 1.7, with a 95% confidence interval of 1.1 to 2.6. The study reported a statistically significant trend across increasing prescription counts, with a trend value below 0.001.
The researchers also examined individual antibiotic classes. The supplied report says that tetracyclines and cephalosporins remained significantly associated with higher odds, but it does not provide further effect estimates in the available source text. Those class-specific findings should therefore be interpreted alongside the broader study design and with caution until the full research record is available.
What the results do and do not mean
Antibiotics are important medicines for bacterial infections, and this study is not evidence that patients should avoid a clinically indicated prescription. The research instead highlights why stewardship matters: antibiotics should be used when they are needed and selected appropriately for the condition being treated.
The study cannot, from its reported results alone, separate a direct effect of antibiotics from the effects of infections, healthcare use or other characteristics linked to antibiotic prescribing. People who receive more prescriptions may differ from those who receive fewer in ways that are relevant to later IBS risk. Adjustment for sex and socioeconomic status is useful, but it does not eliminate every possible source of confounding.
Its value lies in the long time span and the use of recorded data. Participants were followed from late childhood into young adulthood, and the analysis examined both any exposure and cumulative prescription count. That makes the work a substantial addition to an area where researchers have sought better population-level evidence.
Next steps for the evidence
The findings were presented at a medical meeting, UEG Week 2026. Conference presentations can provide an early look at research, but the available report does not substitute for a full peer-reviewed paper with complete methods, analyses and limitations. Further studies will need to test whether the association is reproduced in other populations and determine how much is attributable to antibiotic exposure itself versus the illnesses and circumstances surrounding treatment.
For now, the Swedish cohort data support a cautious conclusion: recorded antibiotic use from childhood through early adulthood was associated with higher odds of IBS at 24, and higher prescription counts were associated with progressively higher odds. The result is a reason for continued research and careful prescribing, not a basis for withholding necessary treatment.
This article is based on reporting by Medical Xpress. Read the original article.
Originally published on medicalxpress.com
