Chris - this is an acute situation rather than a constitutional problem which is the reason for the poseology suggested. I have used this schedule many times and have yet to have any problems with it except a positive outcome. Conservatively using Symphytum in potency will mean that a fracture is healed in 2/3rds of the time but I often find it is even better than this.
Synphytum, as the herb Comfrey is difficult to obtain as it can cause problems when taken as the raw herb for a long time. In this case we are talking about taking it in a homeopathic potency which does not cause problems. However I have to say that a weak tea made from the herb does a good job in alleviating stomach tenderness if taken occasionally.

__________________
RSHom - Registered Homeopath