<prompt> A patient presents with lower gastrointestinal bleed. Sigmoidoscopy shows ulcer in the sigmoid. Biopsy from this area shows flask-shaped ulcers. Which of the following is the most appropriate treatment?Intravenous ceftriaxoneIntravenous metronidazoleIntravenous steroids and sulphasalazineHydrocortisone enemas  <response>: Ans. is b i.e., Intravenous metronidazoleRef: Harrison, 18the, p. 1686; 17the, p. 1278 Flask-shaped ulcer in a patient of GI bleed suggests amoebiasis amoebic dysentery. Metronidazole or Tinidazole are the DOCs. 