Fecal incontinence
Fecal incontinence (FI), also known as anal incontinence, or in some forms encopresis, is a lack of control over defecation, leading to involuntary loss of bowel contents—including flatus (gas), liquid stool elements and mucus, or solid feces. FI is a sign or a symptom, not a diagnosis. Incontinence can result from different causes and might occur with either constipation or diarrhea. Continence is maintained by several interrelated factors, including the anal sampling mechanism, and usually there is more than one deficiency of these mechanisms for incontinence to develop. The most common causes are thought to be immediate or delayed damage from childbirth, complications from prior anorectal surgery (especially involving the anal sphincters or hemorrhoidal vascular cushions), altered bowel habits (e.g., caused by irritable bowel syndrome, Crohn's disease, ulcerative colitis, food intolerance, or constipation with overflow incontinence), and receptive anal sex. An estimated 2.2% of community dwelling adults are affected.
Erection
Erectile dysfunction occurs for a variety of reasons. Please see below and also refer to the separate entry on erectile dysfunction and the references therein. Ultimately, the cause for erectile dysfunction is that not enough Nitric oxide (NO) is released by the vascular endothelium of the branches of the perineal artery, a branch of the internal pudendal artery. 
Erectile dysfunction can occur due to both physiological and psychological reasons, most of which are amenable to treatment. Common physiological reasons include diabetes, kidney disease, chronic alcoholism, multiple sclerosis, atherosclerosis, vascular disease, and neurologic disease which collectively account for about 70 percent of ED cases. Some drugs used to treat other conditions, such as lithium and paroxetine, may cause erectile dysfunction.