Bad Body Odor – Causes of Fecal, Fishy and Foul Smell

A bad body odor may not only be due to the odor from the skin. Halitosis (bad breath), offensive groin odor and even bad foot odor are all factors to consider in body odor. In close proximity to others, even odors in concealed areas may be detectable. Offensive smelling discharge from any orifice, even the ear, may be responsible for bad body odor.

Most cases of skin odor is associated with break down of the compounds found in sweat by bacteria that live on the skin. This process is further explained under Body Smell. Excessive perspiration (hyperhidrosis) will exacerbate this effect as larger quantities of sweat are available for bacterial consumption. Hyperhidrosis may be caused by a number of physiological and pathological factors. A bad odor associated with sweating is known as bromhidrosis. It can be generalized or localized to areas like the armpits.

Causes of a Bad Body Odor

Foul Body Odor

Although a foul odor is a general term for any offensive smell, the odor may vary in character and intensity. It may be described by a number of terms, including musty, mousy, fishy, putrid, fetid, fecal or sickening sweet odor.

The causes of foul body odor in general may be due to the following causes :

  • Bromhidrosis (also known as ozochrotia or osmidrosis is mentioned above)
  • Poor hygiene
  • Tobacco smoking
  • Alcohol consumption
  • Topical applications
  • Foul odor from clothing
  • Causes of halitosis (bad body odor)
  • Discharge from the penis, vagina, ear, nose
  • Skin infections, abscess
  • Incontinence, urinary or bowel
  • Medical conditions resulting in waste products being passed out through sweat :
    • Uremia (urea) – kidney failure (fishy or ammonia odor)
    • Ketoacidosis (acetone) – diabetes or starvation (sickly sweet odor)
    • Fetor hepaticus (methyl mercaptan) – liver failure (stale, must or mousy odor)

Fishy Body Odor

A fishy odor is often attributed to ammonia. In the body this is related to urea, a nitrogenous compound formed by the break down of protein. A fishy odor is often a result of high levels of urea, as is seen in uremia. This occurs when the kidneys are not able to remove the urea that builds up in the body through urine. Uremia is indicative of kidney disease and patients may even have a fishy smelling breath.

Fishy odors have often been attributed to menses (periods). This may not be a characteristic odor for every woman during menstruation or on every period. When it does occur, it may be associated with poor hygiene (infrequent changing of sanitary pads), obstruction of menstrual blood outflow and a range of infectious causes. It is likely a result of  bacteria consuming any menstrual blood or clots, but may also be associated with leukorrhea, which is a thick white to yellow discharge seen with bacterial infections like bacterial vaginosis.

Fishy odors may also be seen with UTI’s (urinary tract infections) in both men and women, especially if a urethral discharge is present. Urinary incontinence and post-micturition dribble with appropriate measures taken to change the underwear may be another cause of a fishy odor.

Fecal Body Odor

A body odor that resembles feces is often a result of fecal matter being present on the skin surface or clothing. This may be seen with diarrhea, inadequate cleaning after defecation, and in patients who are debilitated, the elderly and those with mental diseases, who are not able to visit a toilet to relive themselves. A possible cause of a fecal body odor is a gastrocolic fistula, where a fecal smell to the breath may be noticed. Patients with a stoma may also have to be monitored if a fecal body odor occurs as it may be a sign of some dysfunction.

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