Small bowel obstruction: is routine colonoscopy necessary after resolution?

Small bowel obstruction is common in clinical practice and is most often due to adhesions. The aim of this study was to determine the significance of colon cancer presenting as a small bowel obstruction at a single institution and to find out whether routine colonoscopy was necessary in patients who had spontaneous resolution of their small bowel obstruction.

A retrospective review of the medical records of patients presenting with small bowel obstruction from 1995 to 2000 at the Prince of Wales Hospital was performed. The clinical outcomes were obtained from the medical records and the clinical notes of each surgical consultant.

Over the study period, 251 patients presented with small bowel obstruction. The mean age at presentation was 63.8 years (range 21-95 years). A total of 149 patients (59.4%) were treated conservatively with an average hospital stay of 4.6 days (range 1-20 days). Another 100 patients (39.8%) were treated operatively with a mean time from presentation to operation of 2.2 days (range <24 h-14 days). The remaining two patients (0.8%) were managed palliatively because of known metastatic disease. At laparotomy, 13 patients (13%) had a colon cancer identified. A further three patients were identified to have a colon cancer on follow up colonoscopy. However, only one of the three patients had had a previous laparotomy, that is, only 0.7% (1/149) of patients with a spontaneously resolved small bowel obstruction (presumably secondary to adhesions) had actually had colon cancer.

The overall incidence of small bowel obstruction secondary to colon cancer is significant at 6.4%. However, as the incidence of colon cancer in patients who had had a previous laparotomy and spontaneous resolution of their obstruction was very low at 0.7%, routine colonoscopy does not seem warranted.