Yolanda Foster is firing back amid controversy over her and her children's Lyme disease diagnosis'. During an appearance on Bravo's "Watch What Happens Live" the reality star and mother of three took a moment to slam her doubters — specifically her "The Real Housewives of Beverly Hills" co-star Lisa Rinna.

During the show, which aired Tuesday an hour after a drama-filled episode of "RHOBH," Yolanda was asked about Lisa R.'s participation in a conversation about Munchausen Syndrome, a mental disorder in which a person only acts as if they're sick, earlier in Season 6. As was reported by E! Online, Yolanda questioned her co-star's loyalty, telling "WWHL" host Andy Cohen she couldn't understand why Lisa R. would believe something her hairdresser had said. She suggested that her cast mate should have immediately told the stylist those rumors were "'crazy'" before revealing to Andy, 47, that she doesn't even know Lisa R.'s hairdresser. The "WWHL" host then suggested that Lisa R., and anyone else with doubts about Yolanda's Lyme disease, may simply "want to believe you're faking." 

"You know what, they're maybe saying what a lot of people are thinking in the world. I mean, there's such ignorance when it comes to invisible diseases and millions of people are suffering with those problems, of family members, friends and people out in the world judging them by the way they look. So, maybe they're just voicing what a lot of people are thinking," Yolanda said.

Yolanda's Lyme disease — along with the Munchausen's Syndrome drama — has been an integral part of her Season 6 "RHOBH" storyline. During episode 12, the claims resurfaced during a party at new cast member Erika Girardi's house. Yolanda used the party as an opportunity to confront Lisa R. about the Munchausen Syndrome allegation after fully learning what the disease entails. She and Erika teamed up, demanding answers about who told Lisa R. this and why she engaged, but the former soap opera star refused to budge. Lisa Vanderpump and Kyle Richards attempted to defend Lisa R., assuring Yolanda that no one had ever actually said she was feigning her ailment, but their efforts were futile.

The allegations first surfaced during Season 6, episode 4 when Lisa R. popped over to Lisa V.'s home with Kyle and Eileen Davidson. Before Eileen arrived at the house, Lisa R. revealed to her co-stars that she'd heard a nasty story about Yolanda and was feeling guilty about having done nothing to shut it down. She then explained to them what Munchausen Syndrome was, which left both women aghast. Although she never flat out accused Yolanda of having the disease rather than Lyme disease, she did plant the initial seed. 

Yolanda's diagnosis drama will be the subject of an upcoming episode of "RHOBH" as well. Tune in Tuesday at 9 p.m. EST on Bravo for the latest.