The effect of combat rations on bowel habits in a combat environment

Combat rations have long been suspected to affect the bowel habits of deployed soldiers by causing significant constipation. This may create morbidity and result in decreased troop readiness. In a uniform population of deployed combat soldiers, we sought to determine the effect of combat rations on changes in bowel habits.

Over a 4-month period from December 2001 through March 2002, 118 soldiers were followed prospectively using a bowel habit diary. Soldiers were evaluated by age, race, gender, past medical history, ration intake, and medications including fiber use. Subjects were then screened for changes in diarrhea and constipation. We performed an analysis to determine predictors for changing habits.

There were 108 males and 10 females. Mean follow-up was 42.6 +/- 23.1 days. Groups were comparable in demographics, time in the combat zone, and fluid/fiber intake (P = not significant [NS]). No change in habits were found in 58%, 19% had an increase in constipation, 13% had an increase in diarrhea, and 10% had increase in both diarrhea and constipation, while 8% had improvements.

Combat rations and environment have variable effects on bowel habits, with no loss in workdays. Although 64% of subjects experienced either no change or improvement, and 36% had worsened symptoms, this appears unrelated to ration or fiber intake.