09/11/2014 12:53 EDT | Updated 11/11/2014 05:59 EST

Rob Ford has faced frequent health issues while in office

Mayor Rob Ford is said to be staying at Toronto's Humber River Hospital, as doctors work to learn more about the tumour that has been found in his abdomen.

His brother, Coun. Doug Ford, revealed to the public last night that the mayor had been dealing with abdominal pain for about three months. After they went to breakfast on Wednesday, the pain became "unbearable" and Mayor Ford went to hospital. A CT scan led doctors to make a working diagnosis that a tumour is present.

The discovery is the latest in a series of health issues that have afflicted the mayor, who has already sought care in a hospital at least twice this year.

Ford, who turned 45 in May, spent four days in hospital this spring, immediately before he entered a residential treatment program for substance abuse.

Ford's journey into rehab followed a year in which he was accused of and eventually admitted to having smoked crack cocaine. He also admitted to drinking to the point of putting himself in "drunken stupors" and vowed to cease drinking.

After his two-month stint in rehab, Ford came back to work just ahead of Canada Day. But he visited a hospital again in mid-July, to deal with what was said to be a toe injury that had been bothering him for some time. He was supposed to be having surgery for that after the upcoming Oct. 27 election.

In 2012, Ford spent two days at Humber River Hospital for a throat infection that had aggravated his asthma. A photo was tweeted showing the mayor reading a document in his hospital bed.

In February 2011, just a few months after he was formally sworn in as mayor, Ford twice went to hospital to deal with issues relating to kidney stones.

Ford had also been to hospital the year before he was elected mayor to have a tumour removed from his appendix.

"I had a major surgery on my appendix; they took out a piece of my colon. So I had a tumour in my appendix, and that's pretty scary when that happens," Ford told CTV News in an interview in September 2010, the year after that tumour was removed.