An internal scar can cause a hernia when weakness in the abdominal muscle allows the tissues of the abdomen to protrude through the muscle. This "incisional hernia" is a result of an incision made in a prior abdominal surgery. A pulling type pain may be the first symptom, as well as a visible bulge at the scar. Sufferers of this type of hernia may experience more intense symptoms when coughing or sneezing.
Multiple abdominal surgeries, significant weight gain after abdominal surgery, pregnancy, obesity, or activities that may increase pressure to the abdomen (heavy lifting, for example) can place one at a higher risk for an incisional hernia.
Thanks to ENDOGYN for the information regarding incisional hernia.