After postponing her Monday show in Montreal due to an unspecified illness, has also canceled her Wednesday show in Boston and her Thursday one in Philadelphia, according to the venues' Web sites.
The singer suddenly became ill during the sound check for Monday's show and was hospitalized, but was discharged two hours later, according to a spokesperson from Montreal's Royal Victoria Hospital.
"Yesterday evening she was checked into the Royal Victoria Hospital and left a couple of hours later," Rebecca Burns, the spokeswoman for the McGill University Health Centre, which operates the hospital, told People.com on Tuesday.
At press time, the Rock Witchu Tour, which also features LL Cool J, was expected to resume in Greensboro, North Carolina, on Saturday.
It's been a bumpy tour — and year — for Jackson. On Friday, she postponed a show in Detroit due to "production constraints," according to TMZ. Last week, Jackson announced that she would be parting ways with Island Def Jam Records after just 14 months with the label. The singer's publicist noted that the label agreed to dissolve the relationship upon Jackson's request.
In March, Jackson released an album that reflected a return to her mid-'80s Control era in more ways than just the title. But since debuting at #1, the album has sold disappointingly, according to SoundScan. In interviews, Jackson hinted that she was unhappy with the way things were working out with the label.
Monday's ailment isn't the first illness that Jackson has battled this year. In April, while promoting Discipline,, Jackson missed an appearance on "Saturday Night Live" due to illness. Boyfriend Jermaine Dupri told MTV News she had bronchitis.