Factors influencing colonic involvement in patients with amebic liver abscess.

BACKGROUND: The frequency of colonic involvement in patients with amebic liver abscess has not been studied in detail. The factors influencing colonic involvement also are unknown.
METHODS: Seventy-one patients with amebic liver abscess were studied. Colonoscopy was performed in all patients.
RESULTS: Abdominal pain and fever were the most common presenting manifestations. Ten patients (14%) had diarrhea at admission. Ten other patients had a history of diarrhea during the preceding 2 months. Thirty-nine (55%) patients had colonic ulcers. Colonic ulcers were present in 18 of the 20 (90%) patients with ongoing diarrhea or a history of recent diarrhea, and in 21 of 51 (41%) patients without diarrhea (p<0.001). Thirty (42%) patients had small, discrete ulcers in the cecum, the ascending colon, or the region of the hepatic flexure. Nine patients had large, multiple ulcers with surrounding inflammation. In these patients, the ulcers were present either in the left colon (n=7) or throughout the colon (n=2). The mean (standard deviation) age of patients with 5 or more ulcers was significantly greater than that of patients with fewer than 5 ulcers (49.8 [14.6] years vs. 37 [11.7] years; p<0.05). Multiple ulcers were noted in 7 of the 10 patients (70%) with diarrhea at admission and in two of the 61 patients (3%) in whom diarrhea was not a presenting symptom (p<0.001). No association was noted between the location of the abscess in the liver and the colonic lesions.
CONCLUSIONS: Colonic ulcers are a common finding, occurring in more than half of patients with amebic liver abscess. They are more likely to be present if the patient has diarrhea as a presenting symptom or has had diarrhea in the recent past. Multiple, large, and left-sided ulcers are more common in elderly patients and in those in whom diarrhea is the presenting symptom. However, there is no association between the location of the abscess in the liver and colonic lesions.