5.11Irritable Bowel Syndrome and Other Gastro-Intestinal Disorders

5.11Irritable Bowel Syndrome and other gastro-intestinal disorders

5.11.1Irritable Bowel Syndrome and other gastro-intestinal disorders at follow up

Irritable Bowel Syndrome measured using Rome III criteria at follow up

Ninety Gulf War veterans (13.3%) and 52 comparison group participants (8.1%) met Rome III criteria for Irritable Bowel Syndrome (IBS)58 in the three months prior to follow up. The difference between the two groups was statistically significant with Gulf War veterans at 64% greater risk of Rome III IBS; RR 1.65, adj RR 1.64, 95% CI 1.18-2.27. Additional analysis excluding participants who reported that they had Colitis or Crohn’s disease, which might explain IBS symptoms, caused little change in the difference between the two groups; adj RR 1.67, 95% CI 1.19-2.38. Among those who met Rome III IBS criteria, 4% of the Gulf War veterans and 8% of the comparison group participants had constipation; 25% in both groups had diarrhoea; and 70% and 67% respectively had IBS of mixed type.

Self-reported doctor diagnosed or treated gastro-intestinal disorders at follow up

IBS and other gastrointestinal disorders which were self-reported by respondents to have been diagnosed, or treated, by a medical doctor since January 2001 are shown in Figure 24.

S MNHS SPHPM EPM MonCOEH GULF WAR 2010 FOLLOW UP Data Analysis Follow Up Health Survey IBS andOtherStomachDisorders IBS medconditions chart2 png

Figure 24 Self-reported doctor diagnosed or treated gastrointestinal disorders since 2001

The most prevalent gastro-intestinal disorders were stomach or duodenal ulcers, reported by 5% of the Gulf War veterans and 3.7% of the comparison group. Other gastro-intestinal disorders were very infrequently reported. Only 6 participants in total (1.7%) reported doctor-diagnosed, or treated, IBS. There were no statistically significant differences between the two groups in regard to any of the self-reported doctor-diagnosed gastro-intestinal disorders in Figure 24.

5.11.2Association between Gulf War-deployment characteristics and Irritable Bowel Syndrome in veterans at follow up

The associations between Gulf War deployment characteristics and the presence of Rome III IBS at follow up in Gulf War veterans are shown inTable 45.

Table 45Association between Gulf War-deployment characteristics and Rome III IBS at follow up in male Gulf War veterans

Gulf War veterans with IBS at follow up
Gulf War exposure / N / n (%) / RR / Adj RR(95% CI)
Age at deployment
< 20 / 61 / 7 (11.48) / 1.00 / 1.00
20-24 / 161 / 25 (15.53) / 1.35 / 1.74 (0.79-3.83)
25-34 / 355 / 48 (13.52) / 1.18 / 2.19 (0.95-5.04)
>=35 / 98 / 10 (10.20) / 0.89 / 1.98 (0.70-5.64)
Service branch
Navy / 580 / 77 (13.28) / 1.00 / 1.00
Army / 44 / 6 (13.64) / 1.03 / 1.29 (0.60-2.76)
Air Force / 51 / 7 (13.73) / 1.03 / 1.22 (0.59-2.49)
Rank category
Officer / 144 / 11 (7.64) / 1.00 / 1.00
Other rank-supervisory / 346 / 45 (13.01) / 1.70 / 1.76 (0.90-3.42)
Other rank - non supervisory / 184 / 34 (18.48) / 2.42 / 3.34 (1.58-7.05)

Gulf War veterans with Rome III defined IBS at follow up were significantly more likely to have been in a non-supervisory rank at the time of the Gulf War deployment, compared to higher ranks. There was no association between Rome III defined IBS at follow up and age or service type at deployment.

5.11.3Key findings

Thirteen percent of Gulf War veterans and 8% of comparison group participants met Rome III criteria for IBS in the three months prior to follow up. This represented a statistically significant 64% increase in risk of IBS amongst Gulf War veterans relative to the comparison group. Less than one percent of participants in both study groups, however, reported doctor-diagnosed or treated IBS since 2001. While it is acknowledged that the instrument used to identify IBS is not a diagnostic instrument, these findings could indicate that study participants are not reporting symptoms of IBS to medical doctors, or that medical doctors are not identifying IBS as the condition underlying the reported symptoms or a combination of both.

There were no statistically significant differences between the groups in regard to any of the self-reported doctor-diagnosed or treated gastro-intestinal disorders, but numbers were small. The most frequently reported doctor-diagnosed or treated gastro-intestinal disorder was stomach/duodenal ulcer which was reported by approximately 4% of all participants and for which the difference between the two groups was the greatest. Other gastro-intestinal disorders were very infrequently reported in each group.

Relative to Officers, Gulf War veterans who served with a non-supervisory rank at the time of the Gulf War were in excess of three times more likely to have met Rome III criteria for IBS. There was no association between Rome III IBS at follow up and age or service branch at deployment.

Australian Gulf War Veterans’ Follow Up Health Study: Technical Report 2015 Page 1