Clinical effectiveness of daikenchuto (TJ-100) on gastrointestinal symptom after colectomy in colorectal cancer patients with abdominal pain and distention due to a bowel movement disorder.

Interventions: Oral administration of test drug (daikenchuto) 5.0 g per dose as a general rule (15 g/day, t.i.d., before meals) from patiant consent day to preoperative day and postoperative day 2 to postoperative day 28.
Standard of care.
Primary outcome(s): 1) Gastrointestinal symptom. (abdominal pain /distention/ the sensation of incomplete bowel evacuation)2) number of postoperative day to comfirm first evacuation, number of postoperative time to comfirm first flatus, number of bowel movements per day.
Study Design: Parallel Randomized