Entamoebahistolyticais one of the common diseases that causes amebic dysentery and liver abscess.The life cycle has two stages: the motile ameba (trophozoite).The mature trophozoite has a single nucleus with an even lining of peripheral chromatin and a prominent central nucleolus (karyosome).The trophozoite is found within the intestinal and extra intestinallesions also in diarrheal stools. The cystno motile cyst predominatesdoesn't found in diarrheal stools. These cysts are not highly resistant and are readily killed by boiling but not by chlorination of water supplies. The cyst has four nuclei, an important diagnostic criterion. Excystation in the intestinal tract, an ameba with four nuclei emerges and then divides to form eight trophozoites. The organism is acquired by ingestion of cysts that are transmitted primarily by the fecal–oral route in contaminated food and water. Anal–oral transmission (e.g., amongmale homosexuals) also occurs.The ingested cysts differentiate into trophozoites in the ileum but tend to colonize the cecum and colon. The trophozoites invade the colonic epithelium and secrete enzymes that cause localized necrosis. As the lesion reaches the muscularis layer, a typical “flask-shaped” ulcer forms that can undermine and destroy large areas of the intestinal epithelium.Progression into the submucosa leads to invasion of the portal circulation by the trophozoites. The most frequent site of systemic disease is the liver, where abscesses containing trophozoites form.Infection by E. histolyticais found worldwide but occursmost frequently in tropical countries, especially in areaswith poor sanitation. About 1% to 2% of people in theUnited States are affected. Infection is common in menwho have sex with men.The Clinical Findings according toacuteinfection in intestinal that causesamebiasisin presents as dysentery (i.e., bloody, mucus-containing diarrhea) accompanied with lower abdominal discomfort, flatulence, and tenesmus. Chronic amebiasis with low-grade symptoms such as occasional diarrhea, weight loss, and fatigue also occurs. Roughly 90% of those infected have asymptomatic infections, but they may be carriers, whose feces contain cysts that can be transmitted to others. In some patients, a granulomatous lesion called an amoebamay form in the cecal or recto sigmoidareas of the colon. These lesions can resemble an adenocarcinoma of the colon and must be distinguished from them.Amebic abscess of the liver is characterized by rightupper- quadrant pain, weight loss, fever, and a tender, enlarged liver. Right-lobe abscesses can penetrate the diaphragm and cause lung disease. Most cases of amebic liverabscess occur in patients who have not had overt intestinal amebiasis. Aspiration of the liver abscess yields brownish-yellow pus with the consistency of anchovy-paste.Diagnosis of intestinal amebiasis rests on finding either trophozoites in diarrheal stools or cysts in formed stools.Diarrheal stools should be examined within 1 hour of collection to see the amoeboid motility of the trophozoite. Trophozoites characteristically contain ingested red blood cells. Two tests are highly specific for E. histolyticain the stool: one detects E. histolyticaantigen and the other detects nucleic acids of the organism in a PCR-based assay. Serologic testing is useful for the diagnosis of invasive amebiasis. The indirect hemagglutination test is usually positive in patients with invasive disease but is frequently negative in asymptomatic individuals who are passing cysts.