In a statement on Friday, the party told the government to adopt democratic values and justice. The party said dictatorial tendencies are unsustainable in modern civilization.
"We are saddened that after leaving custody with injuries Hon Kyagulanyi was stopped from leaving Uganda, and in the most callous and inhumane manner," reads part of the statement.
The statement was signed by ODM Secretary General Edwin Sifuna and Chairman John Mbadi.
"We have been monitoring the situation quietly with the expectation that the various interventions from across the world would bring pressure to bear on the regime to do the right thing. But we are now forced to speak out due to the deterioration of affairs in the country," they said.
Kyagulanyi, popularly known as Bobi Wine, and Mityana Municipality MP Francis Zaake were on Thursday blocked by police at Entebbe Airport.
The two were instead taken to Kiruddu General Hospital.
Ugandan media quoted Kyagulanyi's relatives as saying he was scheduled to travel to the US for scans on a problematic hip pain and in the organs following the serious injuries he suffered at the hands of the police in Arua.
The media reported that Zaake was heading to India for specialised treatment after doctors at Lubaga Hospital said they could no longer help him.
Security officials confiscated his travel documents and those of his wife. They directed him to seek clearance from the Criminal Investigations Department first.
The two politicians are among Opposition MPs and civilians who were violently arrested for allegedly stoning President Yoweri Museveni’s motorcade during chaotic campaigns in Arua on August 13.
ODM said the rights, dignity and freedom of the politicians should be respected by Museveni's regime.
"We will keep an eye on these unfolding events, as we encourage the forces of democracy and peaceful revolution to remain unwavering and firm in their resolve to make our countries more responsive to the needs of their people," the statement added.
The party said events in Uganda have an impact in Kenya by virtue of Uganda being a member of the East African Community.
They said the stability of the country, or lack thereof, often times affects Kenya.