What are the symptoms of ascites? What does it look like? Is it ever associated with autoimmune disease

[Nemos]

Does it only show up in your abdomen, or on your back, above your buttocks, as well?

[tinmuning]

For mild ascites, often it's unnoticeable. Severe ascites are associated with abdominal distention, progressive abdominal heaviness and pressure as well as shortness of breath due to mechanical impingement on the diaphragm.

As for your question on ascites & automimmune diseases: some patients with lupus (about 10%) complain of ascites.