Janet Jackson has been hospitalized due to an unspecified illness, according to TMZ. The singer, who is currently out on her Rock Witchu Tour, "got suddenly ill during the sound check" in Montreal and had to be rushed to the hospital, a rep for W&W Public Relations told the Web site.

Jackson is currently being monitored, but at press time no further information had been given about her illness or condition. E! Online reports that the singer hopes to reschedule the tour stop.

It's been a bumpy year for the singer. On Friday, she called off a show in Detroit due to "production constraints," according to TMZ. She plans to reschedule that stop as well. The tour, which also features LL Cool J, is slated to continue through October 22.

Last week, Jackson announced that she would be [article id="1595401"]parting ways with Island Def Jam Records[/article] after just 14 months. The singer's publicist noted that the label agreed to dissolve the relationship upon Jackson's request.

"Now, more than 20 years after the release of her iconic album, Control, Janet will have autonomy over her career, without the restrictions of a label system," Jackson's publicist said in a statement.

In March, Jackson released [article id="1581513"]Discipline,[/article] an album that reflected a return to her Control era in more ways than just the title. But since [article id="1582799"]debuting at #1[/article], the album has sold a disappointing 415,000 units, according to SoundScan. In interviews, Jackson hinted that she was unhappy with the way things were working out with the label.

This isn't the first illness that Jackson has battled this year. In April, while promoting Discipline, Jackson [article id="1585166"]missed an appearance on "Saturday Night Live."[/article] When MTV News caught up with her boyfriend, producer Jermaine Dupri, at the time, he said, "She's 100 percent better now. She was really sick. She had bronchitis. She's in Japan right now. She's better and doing all the promotion that she didn't get to do because she was sick when the album launched."