In a message to fans, the Good Morning America host, 51, says she's back at home after being treated for a latent virus that had not responded to medication.
"Our immune systems usually take care of a virus like this ... but mine is only 59 days old," Roberts, who had a bone marrow transplant on Sept. 20, wrote in a post called "Home Sweet Home: Part II."
Roberts, who had undergone breast cancer treatment five years ago, was diagnosed this year with a rare blood disorder, myelodysplastic syndrome.
Her sister Sally-Ann Roberts, a broadcast journalist at WWL-TV in New Orleans, donated her healthy stem cells for Roberts's transplant. Her own cells were destroyed by the chemotherapy that was a part of her treatment.
"Physically I felt fine but being back in the hospital took an emotional toll on me," Roberts wrote of her most recent visit. "The wonderful doctors, nurses and support staff lifted my spirits. ... It was comforting seeing them again."
Sally-Ann flew to New York and interviewed her before Roberts was discharged from the hospital on Friday night. The segment will be broadcast on GMA Tuesday morning.
Roberts also recently Tweeted back and forth with Miss America contestant Allyn Rose, who decided she will undergo a double mastectomy as a preventative measure after learning she carries the same chromosomal disease as her late mother, who died of breast cancer.
"Proud of Miss DC @AllynRose, being proactive in fighting breast cancer," Roberts Tweeted on Monday morning. "Admire your courage & candor sharing your decision w/ us. Blessings."
Responded Rose, 24, "@RobinRoberts Thank you so much! You've been such an inspiration to me. Good thing you weren't here today. I might have fainted. #Starstruck"