People are more likely to be admitted to hospital for diverticulitis in the summer, regardless of the hemisphere they live in.

The study of over 18,000 admissions for acute diverticulitis in the UK, the US and Australia showed a consistent summer peak.

The findings suggest the existence of a shared seasonal risk factor for diverticulitis, the researchers say in their study published in the Diseases of the Colon & Rectum.

Possible explanations included seasonal changes in diet, a seasonal pathogen, or seasonal swings in UV radiation.

Dehydration in summer may also slow colonic transit, resulting in fecal stasis that could increase susceptibility to diverticulitis, they suggested.

“We favour a non-behavioural risk factor, because it seems unlikely that seasonal behavioural changes would be shared robustly over global populations,” they wrote.