Causes and treatment outcome of mechanical bowel obstruction in north eastern Nigeria

Mechanical bowel obstruction is one of the commonest surgical emergencies in the tropics. There has been a recent change in its commonest aetiology from external abdominal hernias to adhesions however data on the subject from this environment are lacking.

To establish the aetiological factors, clinical presentation, treatment methods and outcome of mechanical bowel obstruction (MBO) in Maiduguri.

A retrospective review of all cases of MBO that presented to the surgical services of the University of Maiduguri Teaching Hospital (UMTH) between Jan 1994 and March 2004 was under taken.

There were 372 patients ranging between ages five days and 90 years with a male: female ratio of 2.4:1. The mean age was 34.5 years. Patients below 10 years and those between the third and fifth decades accounted for 227(60%) of the cases. Abdominal pain 330 (88.7%), vomiting 316 (84.8%), and constipation 293 (78.8%) were the main symptoms while tenderness and abdominal masses were common signs. Obstructed external hernias, 131 (35.0%) were the commonest cause of MBO; with indirect inguinal hernia 105, (80.1%) accounting for most hernias. Intraperitoneal adhesions 99, accounted for 26.61% of cases. Other causes in descending order were intussusception 80 (21.5%), malignant colonic obstruction 34 (9.14%) and sigmoid volvulus 11 (2.95%). There were no cases of MBO due to Ascaris worms. Adhesiolysis and bowel resection were the commonest operative procedures performed. Common postoperative complications included wound infection 57 (15.3%) and pneumonia 35 (9.4%). There were 34 deaths; giving a mortality rate of 9.14%.

Strangulated external hernias remain the main cause of MBO though its incidence appears to be falling. The pattern of MBO seems to be affected by changing attitude to and availability of elective operations for external abdominal hernias.