- Report: The fight started inside the house and spilled onto the front yard
- Both men were taken to hospital in separate ambulances
Thomson got into an altercation
Wednesday with his sibling at a home in Clive, police told CNN affiliate KCCI.
The fight started inside the house and spilled onto the front yard, prompting a neighbor to call authorities.
Both men were taken to hospital in separate ambulances, according to the affiliate.
It said the musician was wounded at the back of his head, but did not specify what kind of injuries his brother, Andrew Thomson, suffered.
The band's frontman, Corey Taylor, tweeted that the guitarist is doing well.
Slipknot released a new album, The Gray Chapter, in October.
It's scheduled to start its U.S. tour in April
before heading to Europe in June.