Barangay Colunguan

Situated in Santo Tomas, Isabela, Barangay Colunguan is one of 27 barangays that make up the municipality within Cagayan Valley.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay Colunguan had a population of 1,161. This made it the 8th largest of 27 barangays in Santo Tomas by population, placing it in the upper half of the municipality. Residents of Barangay Colunguan accounted for approximately 4.73% of the total population of Santo Tomas, which stood at 24,528 in the same census year.

The barangay recorded 1,184 residents in the 2015 intercensal count and 1,161 residents in the 2020 Census — a net change of -1.9%, consistent with a broadly stable settlement. The Philippine Statistics Authority classifies Barangay Colunguan as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Santo Tomas is a municipality comprising 27 barangays, and serves as the governing unit directly responsible for local services in Barangay Colunguan, including public health, sanitation, peace and order, and civil registration. Within the wider province of Isabela, which contains 1,055 barangays across its component cities and municipalities, Barangay Colunguan ranks 560th by 2020 population. Isabela is classified as a 1st by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

The barangay's legislative and executive affairs are handled by a Punong Barangay and the Sangguniang Barangay, elected nationwide during the Barangay and SK Elections. The next BSKE is scheduled for Monday, November 2, 2026, following the synchronized election schedule set by COMELEC Resolution No. 11191.