Infection with intestinal whipworms (Trichuris spp.) causes widespread morbidity and may alter responses to enteric and extraintestinal coinfections. Here, we show that Trichuris muris infection in mice increases coinfection with 2 evolutionary divergent enteric pathogens, the bacterium Citrobacter rodentium and the helminth Heligmosomoides polygyrus. Coinfection caused reduced weight gain and promoted type 1–biased inflammation. In contrast, T. muris–infected mice were more resistant to migrating Ascaris suum larvae in the lungs. Our results highlight the divergent nature of pathogen interactions and suggest that whipworm infection is a risk factor for coinfections with other pathogens within the gastrointestinal tract.