Objective To investigate whether there has any difference of gastric and small bowel transit time and completion rates between two capsule endoscopes with different size and weight. Methods Clinical data of patients who had undergone OMOM or MiroCam (smaller and lighter than OMOM) capsule endoscopy were retrospectively studied. Comparison of gastric and small bowel transit time and completion rates were made between the two kinds of capsule endoscopy. Results 1, 448 patients (628 in OMOM group and 820 in MiroCam group) were finally includ-ed. In patients with Crohn's disease or suspected Crohn's disease, gastric transit time of OMOM was significantly longer than that of MiroCam [(53.4 ± 52.6) minutes vs (41.1 ± 47.9) minutes, = 0.022]. In patients with gastroin-testinal bleeding, gastric transit time in OMOM was significantly shorter than that in MiroCam [(42.1 ± 44.8) minutes vs (62.0 ± 78.6) minutes, = 0.016). No significant difference in small bowel transit time or completion rate was found. Conclusions We conclude that the differences of gastric transit time, small bowel transit time and completion rates between the two kinds of capsule endoscopy with different size and weight are not significantly. Whereas, in patients with Crohn's disease or suspected Crohn's disease, gastric transit time of smaller and lighter capsule en-doscopy is shorter in patients with gastrointestinal bleeding, but longer of gastric transit time in smaller and lighter capsule endoscopy.