Clinical factors influencing patency capsule excretion and confirmation in patients with intestinal patency

The PillCam™ patency capsule is useful to prevent capsule endoscope retention; however, visual confirmation of patency capsule excretion is challenging for many patients.

We investigated the factors related to the patency capsule remaining in the colon after 33 h and the factors hindering the visual confirmation of its excretion.

We retrospectively analyzed 498 patients with intestinal patency who underwent patency capsule examination. Patients were categorized into the "excretion group" and "colon group," depending on whether the capsule was excreted or remained in the colon after 33 h, respectively. Patients were further classified into self-confirmed and non-self-confirmed groups within the excretion group. Univariate and multivariate logistic regression analyses were used to analyze the factors associated with the colon and unself-confirmed groups.

Overall, 49% of patients visually confirmed capsule excretion within 33 h, whereas 51% did not and required radiological examination. Among those without capsule excretion, 34% of patients had a detectable capsule in the colon, whereas 16% had no detectable capsule. In the excretion group, 75% and 25% of patients were self-confirmed and non-self-confirmed, respectively. Female sex, inpatient status, constipation, and capsule in the colon during the previous examination were independent factors associated with the colon group. Male sex and younger age were the independent factors associated with the non-self-confirmed group.

Our findings highlight the need for new approaches to facilitate patency capsule excretion to avoid radiation exposure, especially in females, inpatients, those with constipation, and those with capsule remaining in the colon from the previous examination.