Both estrogel and utrogestan upset my digestive system in different ways - transit is faster with estrogen, slower with utrogestan. When I first started on estrogel and whenever I have tried to increase, it always causes indigestion, wind, loose poo. Utrogestan on the other hand, gives me increasing reflux and constipation. So both mess with me!! With the estrogen it does ease off though so worth persevering!