To see if closing the mesenteric defects created at a Laparoscopic Gastric Bypass is better than leaving them open.

When the patients who has undergone a Laparoscopic Gastric Bypass lose weight, the mesenteric defects that are inevitable to cause, gets bigger and can cause an internal hernia (IH). This study will observe whether it is better to close the defects or leave them open. The patients will be randomized into two groups. One, where the defects are closed with sutures and one where the defects are left alone. The primary endpoint of the study is the prevalence of surgery for obstruction. Information about this will be gathered through the national register for obesity surgery in Sweden, SOReg. Each arm in the study will include 1200 patients and the follow up period will be three years. Since the register mentioned above is an ongoing register, the results can be studied over a longer period if wanted. The national hospital registry will further improve the follow-up.

Inclusion Criteria:

• Any patient accepted for a Laparoscopic Gastric Bypass that has given a written consent

Exclusion Criteria:

• Conversion to open surgery prior to the randomization
• Patients not giving a written consent