Rectus Sheath Hematoma
This depends on the source. If it is Traumatic, then see S30.0 _ _ _ for Deep Contusion of the Abdomen/Abdominal wall. If it is Not Traumatic, but spontaneous, then see M79.81: Non-traumatic Hematoma of Soft-tissue or Muscle. However, this diagnosis implies some other underlying disease or bleeding disorder that should be identified and coded. If the patient has had abdominal surgery, then this could be a surgical complication: See Complication, Post-procedural, Hematoma, Abdomen.
Respectfully submitted, Alan Pechacek, M.D.