Sometime after its original construction, a new west gable wall was inserted partway along the building's length, cutting the church down by roughly one-third of its original extent. The insertion left the old west end effectively abandoned, and what remains today is a narrow stone structure measuring 17.7 metres long and just 5 metres wide, with a shallow arched doorway in the south wall and a large round-headed window still intact in the east gable. Corbels at the west end, stone projections built into the wall to support horizontal beams, indicate that a loft once occupied this part of the interior. Two of the four windows in the north and south walls have been robbed out over the years, their dressed stone carried off for use elsewhere.

The site is associated with St Colman, the seventh-century bishop who, according to early sources, withdrew from the Synod of Whitby in 664 CE and eventually founded a monastery on Inishbofin. Colman had been defending the Celtic method of calculating Easter against Roman practice, and when the Roman position prevailed, he left Northumbria and brought a community of Irish and English monks to this remote Atlantic island. The precise relationship between that early Christian settlement and the standing medieval masonry is not fully resolved, but a curving scarp line to the north of the church may mark the boundary of an older ecclesiastical enclosure, the kind of earthen or stone perimeter that typically defined early Irish monastic sites. The graveyard itself gathers a remarkable density of early Christian material around the church: two holy wells, several cross-slabs, flat stones incised with cross designs that serve as grave markers, two standing crosses, and a bullaun, a large stone with one or more rounded depressions worn or carved into its surface, often associated with early religious sites and sometimes used in ritual or practical grinding.