There can be several causes for a localized swelling in the buttocks, such as epidermal inclusion cyst, infected lipoma, abscess, boil/furuncle or fibroma. It would be difficult to diagnose without an examination.
An abscess is a localized collection of pus walled off from the rest of the body. It contains pus, which consists of inflammatory cells and decayed tissues. Most abscesses causes local pain and tenderness. A cyst is a fluid-filled cavity, which can present as an infected skin nodule. Both abscess and cyst can develop anywhere in the skin covering the body.
Lipomas are the most common soft tissue tumors that contain fat. They presumably arise from fat that may occur in the back, hips, neck or other parts in adults. An epidermal inclusion cyst is a sac like structure with skin debris inside. These types of swellings are usually not malignant.
You should consult a surgeon for a proper diagnosis and treatment. The diagnosis is through physical findings. Sometimes a needle biopsy or an X-ray, ultrasound, CT or MRI may be done to confirm the diagnosis or rule out any malignant changes. The therapy depends on the location and diagnosis of the swelling. Most of these are small subcutaneous in location and are removed for cosmetic reasons. The treatment is incision and drainage followed by a course of antibiotics. In case of cyst, it is drained and irrigated with a sterile solution.
Hope it helps
I forgot to mention that my first Doctor did think bed bugs and my second Doctor said that it very well could be. I have about 8 of them. They all came at the same time. I checked at the hotel I was staying at and there were other complaints. This is more of a scary situation then anything else. Thank you for your reply. I do have pictures if your interested. I have found online that many Doctors misdiagnose bed bugs because for a long time they were so uncommon. They are an epidemic and spreading at alarming rates. My bites do match up to many pics I have found online. . Also everybody's bites effect them differently. So its hard to diagnose. I do however fit exactly to the descriptions of the bites.They become noticeable almost a day latter so most people don't put two and two together. Then on some including myself they get bigger and turn into red/purplish welts.