True about amoebic colitis is –
**Core Concept**
Amoebic colitis is a type of colitis caused by the protozoan parasite Entamoeba histolytica, leading to inflammation of the colon. The infection occurs when the amoeba invades the intestinal mucosa, causing tissue damage and potentially leading to complications like perforation or abscess formation.
**Why the Correct Answer is Right**
The correct answer involves understanding the pathophysiology of amoebic colitis. Entamoeba histolytica invades the intestinal mucosa by producing cysteine proteinases, which break down the host cell membranes. This invasion leads to the release of pro-inflammatory cytokines, causing inflammation and tissue damage in the colon. The amoeba also adheres to the intestinal epithelial cells through a lectin-like molecule, facilitating its invasion.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because amoebic colitis is not caused by a bacterial infection. While bacterial infections can cause colitis, amoebic colitis is a distinct entity caused by a protozoan parasite.
**Option B:** This option is incorrect because the primary mechanism of Entamoeba histolytica invasion is not through the production of toxins. While toxins may be released during the infection, the primary mechanism involves the production of cysteine proteinases and adherence to intestinal epithelial cells.
**Option C:** This option is incorrect because the primary site of amoebic colitis is not the small intestine. While Entamoeba histolytica can infect the small intestine, the primary site of infection and disease manifestation is the large intestine (colon).
**Option D:** This option is incorrect because the primary treatment for amoebic colitis involves the use of antiparasitic medications, such as metronidazole, rather than antibiotics. Antibiotics may be used in cases of secondary bacterial infection, but they are not the primary treatment for amoebic colitis.
**Clinical Pearl / High-Yield Fact**
A key clinical feature of amoebic colitis is the presence of flask-shaped ulcers in the colon, which can be visualized on endoscopy. These ulcers are characteristic of amoebic colitis and can help differentiate it from other causes of colitis.
**Correct Answer:** C.