Mild infection is asymptomatic. However, heavy infection causes abdominal discomfort and dysentery with blood and mucus in the stools. Amoebae can also cause abscesses in the liver. This presents with an enlarged tender liver. Severe bowel infection can result in perforation and peritonitis.

Amoebae can be seen microscopically in warm stool. A blood test for antibodies against amoebae is useful in identifying patients with amoebiasis.