Correct answer:

If strangulation supervenes, the patient complains of severe pain in the hernia of sudden onset and also of central abdominal colicky pain. The other symptoms of intestinal obstruction – vomiting, distension and absolute constipation – soon appear. Examination reveals a tender, tense hernia that cannot be reduced and has no cough impulse. The overlying skin becomes inflamed and oedematous and there are signs of intestinal obstruction with distension, abdominal tenderness and noisy bowel sounds. These features are much less marked when omentum rather than intestine is contained within the sac. The three common types of hernia to strangulate are, in order of frequency, femoral, indirect inguinal and umbilical.