Matt Roloff, the host of Little People, Big World, recently revealed that his son Zach Roloff is preparing for an “essential” operation.

The 61-year-old reality star shared a photo of Zach with his children on Instagram, along with an explanation that Zach, 32, is revising his shunt.

A shunt is a hollow tube surgically placed in the brain — or occasionally in the spine — to aid in the drainage of cerebrospinal fluid and the redirection of that fluid to another location in the body where it can be reabsorbed, according to John Hopkins Medicine. This procedure may be used to treat a condition known as hydrocephalus.

A shunt revision may relieve pressure on the brain and address symptoms such as difficulty walking, mild dementia, and lack of bladder control; however, the family has not revealed any details about the treatment.

“The family has kept in constant contact and conversation. We pray for Zach as he undergoes this extremely significant modification to his shunt.” Matt wrote the caption for this post. “Tori is fighting tooth and nail for what is best for him, so he is in good hands… Please join me in praying for Zach’s quick and complete recovery.”

Tori, Zach’s wife, also posted about the surgery on her social media account, asking followers to pray for the couple.

Tori, now 31 years old, wrote in an Instagram Story that has since been deleted, “We discovered Zach’s shunt needs repair and will have surgery in the morning.”

The TLC show’s star claimed she “hesitated” in informing her fans, but she did so because “I believe in prayer and might need some tomorrow.”

“Even though they say it’s a routine procedure,” Tori continued, “I have no idea what to expect, and Zach and I are nervous.”

“It appears to be a significant issue, but we have faith in his doctors and their competence and expertise. We would appreciate any prayers you could offer.”