Hemorrhoids are veins in the anus/rectum, which can become dilated (swollen) with increased strain (for example: chronic constipation). Hemorrhoids can be divided into 2 groups. Internal and external. These refer to the their location. Generally speaking internal hemorrhoids do not hurt, whereas external hemorrhoids do. If you have pain when you have a bowel movement, then you may have external hemorrhoids. Some symptoms of hemorrhoids are peri-anal itching, pain, and bleeding
during bowel movements in which you can see drops of red blood in the water of the toilet bowl or on the tissue paper after wiping. There are some over the counter symptom relievers such as Preparation H creams that can be used to decrease symptoms. Sitz baths can also help with symptom control. Stool softeners may also be of value.
Other common entities that can cause pain during a bowel movement are fissures and abscesses. Fissures are small tears in the skin of the anus. These usually happen at the posterior midline (on the back side of the opening). These can also be quite painful and treatment involves stool softeners and possibly a surgical procedure in which a small band of muscle in the anorectal region is cut.
Abscesses are small pockets of infection under the skin. These can sometimes (not always) have drainage. Redness, and localized swelling can be seen in this instance. Treatment for this is to drain the abscess.
Because there are different causes for anal pain, it is recommended that you see a general or a colorectal surgeon
(or at the very least, your primary care physician
), who can perform a quick examination and give a definitive diagnosis and recommend appropriate treatment.