Background: A patency capsule (PC) can help predict capsule endoscope (CE) retention; however, PC tolerability is unknown in children. We retrospectively evaluated PC tolerability in school-aged children. Methods: Sixty-one patients (median age, 12.9 years; range 7.4-17.3 years) who underwent PC examination were analyzed for occurrence and determinants of ingestion difficulty and relationships between ingestion of the 2 capsules. We defined ingestion difficulty as taking 30 min or more, or failure, to ingest the PC. Results: Thirty-nine patients (64%) successfully ingested the PC without ingestion difficulty. The other 22 had ingestion difficulty and were significantly younger (11.7 ± 2.2 vs. 13.0 ± 1.8 years; p = 0.04) and shorter (143.3 ± 14.0 vs. 154.6 ± 12.5 cm; p = 0.003) than those without ingestion difficulty. Multivariate analysis showed that the most significant factor for predicting PC ingestion difficulty was height (cutoff value, 152 cm). Time to ingest the CE was significantly shorter than that for PC ingestion (8 ± 32 vs. 20 ± 58 min; p = 0.01). All patients indicated that ingestion of the CE was easier because of its smooth surface compared with the PC. Conclusions: PC ingestion is not guaranteed in school-aged children. PC ingestion ability should be evaluated by considering the child's height and lack of experience ingesting capsules prior to PC examination.