Clexane is a low molecular weight heparin used as a blood thinner. It is often prescribed for women with unexplained pregnancy losses. It does not cause premature delivery, loose stools or other pregnancy related complications. Redness, irritation, bruising at the injection site, rarely, bleeding, low platelet count, bone loss is seen. Loose stools could be due to some other cause and it needs further evaluation. Stay in touch with your obstetrician to guide you.