Anal masturbation is an erotic stimulation focusing on the anus and rectum. Diverticular disease can present with painless rectal bleeding as bright red blood per rectum. The laceration can be so extensive as to involve the rectum and anus. Men may find stimulation of the anus, rectum, and especially the prostate, pleasurable. This acts to make the angle between the rectum and anus straighter, and facilitate defecation. The large intestine includes the rectum and anal canal. Diseases affecting the rectum and anus are extremely common, especially in older adults. The rectum and sigmoid colon can absorb magnesium. The end of the intestine opens into a short muscular rectum. The vagina is located between the bladder and the rectum. There are several reasons that contribute to the jamming of rectal bodies inside the rectum. Ulcerative colitis is normally continuous from the rectum up the colon. The prostate gland lies under the bladder and in front of the rectum. It relaxes to expel feces from the rectum and anal canal. Severe disease can lead to narrowing of the colon or rectum.