People dressed as doctors and nurses sprinted through a park to raise money to stop bowel cancer.
Volunteers went to Northwick Park, in Watford Road, Harrow, for a 1.5km fun run to raise money for the St Mark's Hospital Foundation.
St Mark's Hospital specialises in treating bowel diseases and the day included activities to educate people about the signs and symptoms of bowel cancer.
The day included musical entertainment and a and was attended by Deputy Mayor of Harrow, Councillor Krishna Suresh.
Rubin Rauf, a radiology assistant at the hospital, said: “It’s a great cause and dressing up in hospital outfits is a fun way to get involved.
“Working at the hospital, you see first hand how important it is to raise money for services and charities.
“It’s nice to see people of all different backgrounds here today.”
The event included a giant inflatable bowel that people could walk through to find out more about the signs of the illness.
Alpa Malde, 48, who took part, said: “I just like helping good causes and it’s really important to educate people about bowel cancer.
“It gives you a chance to make a difference whilst having fun and meeting other people.”
Alex Burton, a community and events fundraiser at St Marks Hospital, said: “Families and children have come out today, and it’s important that a range of people support this cause.
“We’ve had a great turnout so we’re really pleased with how it’s all gone.”