Rob Kardashian 'wants nothing to do with the world' after health diagnosis

Rob Kardashian has reportedly slipped further into seclusion after his Christmas health scare.

"Rob acts like he wants nothing to do with the world," the insider said. "He doesn't respond to texts from people that are genuinely concerned and checking up on him," a source told People.

The former reality star was rushed to the hospital on Dec. 27 with severe stomach problems and diagnosed with diabetic ketoacidosis, a serious condition that can be quelled with a healthier lifestyle.

SEE ALSO: Lamar Odom's son posts first photo of NBA star since overdose

While most of the family has stayed mum on the diagnosis, Rob's sister, Khloé, posted a "melancholy" selfie on Instagram.

It has been business as usual for the family after Rob's hospitalization. Mom Kris is back in St. Barths after jetting back to visit her son in the hospital, and all members of the family celebrated New Year's Eve this week -- Kim with Caitlyn, Kourtney with her kids, Khloé with boyfriend James Harden and Kendall with Harry Styles in Anguilla.

"The family will come up with a new plan when the holiday is over and everyone is back in LA," a source revealed. "They are of course very concerned about Rob and have been for a long time."

As his famous family continued to thrive in the limelight, Rob has only slipped further into seclusion over the past few years.

Rare photos taken of the former reality star over the years show that his weight ballooned, as his family grew concerned over his mental and physical health, as demonstrated on "Keeping Up With the Kardashians."

See Rob through the years:

More on AOL.com
Caitlyn Jenner settles lawsuit with driver in fatal Malibu car crash
Kourtney Kardashian's New Year's resolutions are a little on the sad side
Reaction to the death of Grammy-winning singer Natalie Cole