Clinical efficacy of Daikenchuto (DKT: TJ-100) for gastrointestinal dysfunction following colon surgery (a randomized, double-blind, multi-center, placebo-controlled study)

INTERVENTION: Oral administration of test drug (Daikenchuto) 5.0g per dose as a general rule (2.5g/pack x 2 packs) t.i.d. before meals. May decrease dosage to 7.5g/day (2.5g/pack x 3 packs) according to patient`s symptoms. Oral administration of test drug (placebo) 5.0g per dose as a general rule (2.5g/pack x 2 packs) t.i.d. before meals. May decrease dosage to 7.5g/day (2.5g/pack x 3 packs) according to patient`s symptoms. CONDITION: Colon cancer including RS cancer PRIMARY OUTCOME: 1)Time to first defecation (hr) after nasogastric tube removal ; 2)Postoperative frequency of defecation (number of times/day); 3)Postoperative stool form (Bristol Stool Form Scale) SECONDARY OUTCOME: 1) GSRS Score; 2) FACT‐C Score; 3) CRP; 4) Incidence of postoperative intestinal; obstruction INCLUSION CRITERIA: 1) Patients who qualify for curative colonic resection (solely via laparotomy) for colon cancer (including rectosigmoidal region) Preoperative staging of disease: I, II, IIIa, IIIb TNM category distribution: T=1‐3, N=0‐2, M=0 2) PS (ECOG Performance Status Scale): 0, 1 3) Patients who can orally administration of Daikenchuto 4) Age: over 20 yo. 5) Gender: no specification 6) Inpatient/Outpatient: Inpatient 7) Patients who can provide written informed consent