Hi
Welcome to the eHealth forum!

I read through your post very carefully (left lower abdominal pain, belching, gas, constipation) and based on that I feel that you could be possibly suffering from Celiac Disease/Ulcerative Colitis/Irritable Bowel Syndrome/ Crohn’s disease. All these result in tender abdomen, loose stool or loose stools alternating with constipation, abdominal distention or bloating, gas, cramps etc.

A number of times a gastroenterologist (a doctor who looks after the gut) is able to diagnose these conditions by clinical examination and detailed medical history. At other times a few tests are conducted like blood tests to rule out anemia, stool test to look for white blood cells, sigmoidoscopy, colonoscopy etc. Irritable bowel syndrome is diagnosed by elimination of other causes. Gluten is a complex protein present in four main grains---wheat, rye, barley and oats. If you have gluten intolerance, then you probably have celiac disease or Non Celiac gluten sensitivity.

Swelling and itch in vulva (external genitalia) and itch is seen in Crohn’s disease and IBS. It may or may not be related to your gas issues. There are many other causes too such as thrush, trichomoniasis, psoriasis, eczema, etc.

You can discuss these possibilities with your doctor as on net and without examining it is difficult to give a confirmed opinion. Hope this helps. Take care!