what causes mals
1. Median arcuate ligament syndrome (MALS) or celiac axis compression syndrome (CACS) is an uncommon condition caused by the external compression of the celiac trunk by the median arcuate ligament (Figure 1). This symptom involves abdominal pain, nausea, vomiting, and weight loss.. Discussion. The MALS or CACS is a rare cause of postprandial pain and weight loss. This syndrome was first described by Harjola [ 3 ] in 1963. The incidence of MALS has been found in 10â24% [ 1 ].