Aim of the work This randomized controlled study aims to investigate the effect of botox injection in abdominal wall muscle post major abdominal surgery in terms of postoperative pain, incidence of incisional hernia Study design and setting This is a double-blind prospective randomized controlled trial that will be conducted in the general surgery department and colorectal surgery unit of Mansoura University hospital in the period from June 2019 to June2020. The patient's recruitment process will be started and continued for one year after getting the approval from the local Institutional Review Board in Mansoura University in concordance with the Helsinki Declaration Principals. The data will be collected and analyzed prospectively. A signed informed consent will be obtained from every patient before enrollment highlighting the possible future publication. On request, patients can be excluded from the study at any time if they do not want to continue.

Inclusion Criteria:

-Patients with major abdominal surgery including trauma and elective exploration surgery, damage control surgery.

Exclusion Criteria:

• pregnancy
• patients with myopathies
• motor polyneuropathies, impaired neuromuscular transmission (Myasthenia Gravis)
• complicated Chronic Obstructive Pulmonary Disease (COPD),
• necrotizing fasciitis of the trunk
• unfit for general anesthesia
• patients with psychiatric disorders
• patients with drug abuse or history of opioid intake
• chronic pain disorder
• coagulopathy