Patients undergoing abdominal procedures often require multimodal postoperative pain controls. Truncal blocks such as quadratus lumborum (QL) block may be used adjunctively as a part of it. The investigators hypothesized that the ultrasound-guided QL block with transmuscular approach can provide adequate pain relief for colostomy closure as part of a multimodal pain control.

Inclusion Criteria:

• A physical status between ASA I and III
• 20 - 75 years of age
• Patient has signed an informed consent
• Without contraindication of QL block

Exclusion Criteria

• American Society of Anesthesiologists (ASA) Physical Status ≥ 4
• Any contraindication to nerve blocks (including coagulopathy, abnormal anatomy, infection at the planned QL injection site, and amide-type local anesthetic allergy) pregnancy or breast-feeding
• Severe obesity (body mass index≥ 35 kg/m2)
• Patients with a history of significant neurological, psychiatric, neuromuscular, cardiovascular, pulmonary, renal or hepatic disease
• Allergy to NSAIDs
• Infection at the QL injection site
• Patients with major psychosis or drug and alcohol abuse
• Patient unable to comprehend or use the verbal rating pain scoring system or patient-controlled analgesia pump