Is it a coincidence that i developed gastroparesis and overactive bladder in the same month ? what could be the root of both problems?

Why are you on MTX?: methotrexate may be either causing the symptoms or possibly you have a condition being treated with methotrexate that has resulted in your current symptoms. Without more information that question can't be addressed. You are best off asking your physician about this. Also make sure you are screened for diabetes. Best of luck!

Meds or diabetes: Very interesting constellation of symptoms, as both the stomach & bladder are part of the parasympathetic system, and so activating one tends to activate the other. If there is a neuropathy (nerve dysfunction) from diabetes, it could cause both; also any new medications should be analyzed. Adrenal problems rarely contribute. Talk to a doctor for a diagnosis real soon, and good luck!

Not sure related: Gastroparesis can be idiopathic but is commonly related to diabetes. Are you diabetic and do not know it? The overactive bladder is not related to the gastroparesis and can be spas. Many of the meds for overactive bladder will worsen the gastroparesis. See a gastroenterologist if you have not. It is important as this is quite important with your health problems.

Autonomic neuropathy: The root of both problems could be autonomic neuropathy from conditions that can affect nerves in several places, for example, diabetes, alcoholism, chronic inflammatory diseases.

Gastroparesis: Gastroparesis may have some underlying cause to cause autonomic neuropathy, overactive bladder could be a coincidence. Have seen people with IBS having irritable bladdder also.