Complex sentence: It may also be caused by heavy lifting, vomiting, or even rubbing one's eyes too roughly; in other cases, it may be due to extreme flatulence, or from straining due to constipation.
Split into simpler sentences: It may also be caused by heavy lifting, vomiting, or even rubbing one's eyes too roughly. In other cases, it may be due to extreme flatulence, or from straining due to constipation.