[The main indications for lower endoscopies].

There are three main groups of indications of lower digestive tract endoscopy: (1) endoscopy may be performed to detect adenomatous polyps and thus prevent colorectal cancer by systematic excision of these polyps before they become invasive malignancies; (2) it may also be performed in patients whose symptoms (e.g. pain, diarrhoea or anaemia) may be due to a lesion of the colon. It usually provides evidence of such diseases as colorectal adenocarcinoma, ulcerative colitis, Crohn's disease, pseudomembranous colitis, post-irradiation colitis, collagen colitis, ischaemic colitis or colonic angiodysplasia; (3) finally, emergency endoscopy can be used in case of rectal haemorrhage, where it is often completed by haemostasis, or in case of volvulus, where it removes the occlusion.