Colonoscopy is usually required for the following conditions:
1, change in bowel habits, alternating with diarrhea and constipation.
2, bloody stool, dark red blood stool.
3,Mucus and pus stools.
4, diarrhea.
5, change in stool shape, such as thinning, etc.
6, paroxysmal abdominal distension, colic, etc.