Constipation is a side effect of lack of fiber in the low carb diet. Whole grains, legumes and fruit are the normal sources of dietary fiber, and they are all restricted on the Atkins diet's initial phases.
The type of treatment for reactive arthritis depends on the stage of reactive arthritis. The early stage of reactive arthritis is considered acute (early). Acute inflammation can be treated with nonsteroidal anti-inflammatory drugs (often referred to as NSAIDs). These drugs suppress swelling and pain.
Treating reactive arthritis is mostly symptomatic, with high doses of anti-inflammatory drugs or steroids into affected joints. Testing for and treating any underlying infection is often attempted but in many cases the underlying infection is self limited or can no longer be found.