---
title: "Swedish Kids Who Took More Antibiotics Had Higher Odds of IBS by Age 24"
description: "A study of 2,853 people found an association that grew with the number of prescriptions. Its authors say it doesn’t prove antibiotics cause IBS"
author: "Nate Ledger"
published: 2026-10-20T03:18:05.935Z
modified: 2026-10-20T03:59:39Z
url: https://rews.cc/a/swedish-kids-who-took-more-antibiotics-had-higher-odds-of-ib-502000
language: en
tags: ["health", "antibiotics", "ibm", "microbiome", "science"]
publisher: "Rews (https://rews.cc)"
---

# Swedish Kids Who Took More Antibiotics Had Higher Odds of IBS by Age 24

*A study of 2,853 people found an association that grew with the number of prescriptions. Its authors say it doesn’t prove antibiotics cause IBS*

By Nate Ledger · October 20, 2026 · https://rews.cc/a/swedish-kids-who-took-more-antibiotics-had-higher-odds-of-ib-502000

## In brief

- University of Gothenburg researchers presented the study at UEG Week 2026 in Barcelona on 19 October
- They analysed 2,853 people from Sweden’s BAMSE cohort, with prescriptions tracked from ages 9–11 until IBS was assessed at 24
- Antibiotic users had 1.5 times the odds of IBS after adjusting for sex and socioeconomic status (95% CI 1.0–2.2)
- Odds rose with prescription count, reaching 1.7 for six or more; tetracyclines and cephalosporins stood out
- The authors say the results don’t prove causation and that antibiotics shouldn’t be avoided when needed

Here is a finding that is easy to state and hard to interpret. Swedish children and teenagers who were prescribed antibiotics had about 1.5 times the odds of having irritable bowel syndrome by age 24 compared with those who never were. The more prescriptions they got, the higher the odds. Researchers from the University of Gothenburg presented the work at UEG Week 2026, the United European Gastroenterology congress in Barcelona, on 19 October. [CIDRAP’s Chris Dall reported it](https://cidrap.umn.edu/antimicrobial-stewardship/study-links-antibiotic-use-irritable-bowel-syndrome) that day and [again in its next news roundup](https://cidrap.umn.edu/antimicrobial-stewardship/study-links-antibiotic-use-subsequent-irritable-bowel-syndrome).

The data comes from BAMSE, a cohort that started in Stockholm in 1994. It was set up to study environmental and nutritional factors behind allergies and other chronic conditions, not stomachs. That is how most big cohort studies work. Somebody spends decades following a few thousand children for one reason, and later researchers use the records to answer questions nobody had in 1994. This analysis covered 2,853 participants. According to [the UEG press release](https://www.eurekalert.org/news-releases/1146869), their antibiotic prescriptions were pulled from the Swedish Prescribed Drug Register. The records run from 2005, when the participants were 9 to 11, until one year before IBS was assessed at 24. The researchers tracked whether each person got antibiotics, how many prescriptions they got and which classes of drug.

By 24, 10% of the group had IBS, the common condition behind cramping, abdominal pain, bloating, diarrhea or constipation. Of those with IBS, 87.8% had received antibiotics. Of those without it, 80.2% had.

![A textured illustration combines a blister pack of six coral and teal capsules with winding teal intestines dotted with coral patches on a cream background.](https://rews.cc/img/993dfd2398cba59eca04594e600e2cfaea262168.webp)

That second number is worth a moment. Four out of five people who stayed IBS-free still got antibiotics at some point in their teens or early twenties. In Sweden, a country generally careful about prescribing, never taking an antibiotic is the unusual case. So the study is really comparing a large group of people who got antibiotics with a fairly small group who didn’t. Here is a rough calculation from the rounded percentages, which the researchers did not publish: about 285 people had IBS, and roughly 35 of them never had an antibiotic. About 2,568 people didn’t have IBS, and roughly 510 of them never had one. That puts IBS at around 6% among the never-treated and around 11% among the treated. After the researchers adjusted for sex and family socioeconomic status, the gap works out to the reported 1.5 times the odds. The release gives a 95% confidence interval of 1.0 to 2.2. The bottom of that range is 1.0, which means no effect at all, so the result only just clears the bar.

## The dose-response part

The more convincing part is the trend. Compared with people who never took antibiotics, the release reports odds of 1.3 for one to two prescriptions, 1.6 for three to five and 1.7 for six or more, with a P for trend below 0.001. CIDRAP’s write-up puts the lowest group at two to three prescriptions, which overlaps its three-to-five group. The release’s one-to-two looks like the right version. The release also shows that the lowest group’s interval, 0.9 to 2.0, includes no effect. In epidemiology, a dose-response pattern is one of the signs that an association might be real, though it doesn’t settle anything.

![Three increasingly tall stacks of paper each hold a red and blue capsule, with dark speckled clouds behind them on a textured cream and teal background.](https://rews.cc/img/c0354980c8d9d4226e74a9e07e035734881aab80.webp)

Two drug classes stood out: tetracyclines and cephalosporins. The release says any tetracycline use came with 1.4 times the odds of IBS, with an interval of 1.1 to 1.8. Three or more cephalosporin prescriptions came with 6.0 times the odds, and the interval runs from 1.9 to 18.8. When an interval is that wide, the estimate rests on very few people. It suggests a lot of uncertainty, not that cephalosporins are especially dangerous.

## What it doesn’t show

The authors say plainly that this doesn’t prove antibiotics cause IBS. The obvious problem is that antibiotics don’t get handed out at random. They go to children who are sick, and children who are sick a lot get them a lot. So the six-or-more group differs from the never group in more ways than their prescription history. They had more infections and more doctor visits, and possibly different health, families or habits. Lead author Jessica Sjölund, a physician at Sahlgrenska University Hospital and a Gothenburg researcher, named those very factors as the next thing to untangle:

> “Larger, long-term studies with repeated assessment of IBS over time could help determine whether antibiotic exposure precedes IBS and whether the timing of exposure or type of antibiotic matters. Looking more closely at infections, other health conditions and psychological and family factors could also help clarify what is contributing to the association.”

Note that first point. IBS was assessed once, at 24. The study can’t say whether someone’s symptoms started before or after a given prescription. It is possible some people were already having gut trouble, saw doctors more often and picked up more prescriptions along the way.

![A seated person in a coral sweater holds their abdomen beside a tangled stethoscope and a capsule on a cream table.](https://rews.cc/img/63fc18e3cdcd2f5bc3fdfc9d7c626386b71d616e.webp)

The case for a real link rests on the gut microbiome. Antibiotics have long been suspected as an IBS trigger because they disrupt gut bacteria, but past studies linking the two have been mixed. In the release, Sjölund says antibiotic-driven changes to the microbiome may last for years and may be stronger after repeated courses. She argues this study is better than earlier ones because the exposure was “objectively recorded from childhood and adolescence” in a register. Earlier work relied on people remembering what they took, or on finding IBS only in specialist records. She describes the results as something that would “strengthen the epidemiological evidence for a potential link”. That is a carefully modest claim, and the results don’t support anything bolder. It was a conference presentation, not a peer-reviewed paper.

## So should you skip the amoxicillin?

No, and the researchers say so too. In the release, Sjölund says antibiotics remain an important and sometimes essential treatment for bacterial infections, and the findings shouldn’t put anyone off them when they’re needed. Her takeaway is narrower: possible long-term effects from repeated courses are one more reason to avoid unnecessary prescriptions.

That fits a long-running problem in antibiotic stewardship. When a doctor writes an unnecessary prescription, the costs are spread out and come later: resistance across the population and, maybe, a gut problem a decade on. The benefits are immediate: a parent who leaves satisfied and an appointment that ends on time. Stewardship programmes exist to push back against that imbalance. A study like this one adds a modest, uncertain cost to the far side of the scale, which is where those costs usually sit.

## Sources

- [Antibiotic use linked to higher odds of irritable bowel syndrome](https://cidrap.umn.edu/antimicrobial-stewardship/study-links-antibiotic-use-subsequent-irritable-bowel-syndrome) — cidrap.umn.edu
- [Study links antibiotic use with irritable bowel syndrome](https://cidrap.umn.edu/antimicrobial-stewardship/study-links-antibiotic-use-irritable-bowel-syndrome) — cidrap.umn.edu