Radiation therapy is associated with several potential side effects, as shown in this chart.

Skin irritation at the site or radiation entry into the body, with possible blistering or peeling of skin
Problems with wound healing if radiation was administered prior to surgery
Nausea
Rectal irritation, which can cause diarrhea, painful defecation, or rectal bleeding
Bowel incontinence
Bladder irritation causing urinary frequency, dysuria, or hematuria
Fatigue
Erectile dysfunction or vaginal irritation
Scarring, fibrosis, or local adhesions