The appropriate specialist to see for the mesenteric panniculitis would be a Gastroenterologist. There are various types and severity of presentation of mesenteric panniculitis, and the treatment will vary according to the specific presentation. Treatment may include steroids, immune suppressants, such as cyclophosphamide or azathioprine, hormonal treatments, such as progesterone or tamoxifen, or antibiotics. In most cases, the kidney surgery would require more urgent attention than the mesenteric panniculitis, but there should be some level of evaluation to assure that there is no need for surgical intervention of the mesenteric panniculitis. Specifically, there may need to be a surgical biopsy or if there is extensive damage, there may need to be surgical resection, so it is better to coordinate the evaluation and management of the two problems.