Steatorrhea is a medical term used to refer to fat in stool. The presence of fat in stool can cause floating of bulky stool. Fat in stool may also cause greasy or oily appearance as well as foul smell. When the normal process of fat absorption in body is disrupted, it may result to fat passing together with stool. Steatorrhea may be temporary or persistent. Temporary steatorrhea can occur due to intestinal infections or dietary changes. When the condition persists, it may be due a disease of pancreas, intestine, or biliary tract.
Fat absorption and bile
Fat absorption is facilitated by bile, which is synthesized in the liver and transported to the gallbladder for storage. Enzymes like pancreatic lipases are also involved in the fat absorption, as they are responsible for breakdown of fat. The normal functioning of intestine also takes part in the absorption of fat. Absence of bile could cause stool to appear pale color with fat.
Blockage of biliary tract may cause absence of bile. Fat absorption involves a combination of digestive enzymes, bile salts, and unharmed mucus of intestines in order to facilitate the absorption of hydrophobic complexes. Lipids are initially emulsified and hydrolyzed by pancreatic lipase, gastric lipase as well as colipase.
Hydrolyzed lipids are then aggregated into lipid molecules called micelles and bile salts added in jejunum and duodenum. Micelles are then absorbed through passive and active processes and through the lymphatic system, the transportation of micelles occurs where they inter into the circulation. When these processes are disrupted, it decreases the uptake of fat and leads to steatorrhea or at times fatty diarrhea.
Causes of steatorrhea
Steatorrhea falls under three broad etiological groups and the first one involves steatorrhea caused by pancreatic deficiency where there is insufficient production of lipase and colipase to allow for the normal hydrolysis of the lipids. This form of steatorrhea takes place because of absence of acinar cells and chronic pancreatitis. Acinar cells are found in the pancreas and they aid in synthesizing, storing, and secreting digestive enzymes.
The second etiological group of steatorrhea is that which is caused by insufficiency of bile salt due to impaired secretion of bile acids to circulation system. The third group is due to malabsorption of fat caused by medication, disorders of small intestines, and surgeries.
Conditions affecting the intestines may cause steatorrhea including parasitic, bacterial, or viral infection of gut. A patient who has had weight loss surgery or bariatric surgery may also have issues with fat absorption. Celiac disease, which is due to sensitivity to gluten, may cause damage to intestinal walls thus interfering with the process of fat absorption.
Inflammatory bowel disease such as ulcerative colitis and Crohn’s disease may also cause the problem. Shortening of intestine also known as short-bowel syndrome is also implicated in steatorrhea. Conditions that affect the biliary system may also impact on normal process of fat absorption. Biliary atresia, a condition present at birth may cause the development of bile ducts to fail interfering with the movement of bile to the intestine.
Biliary stricture or constricting of common bile duct may also prevent smooth flow of bile. Common bile duct is the tube that receives bile from liver and gallbladder and transports it to the intestines. Gallstones and cancer of biliary tract and gallbladder may prevent bile from flowing to the intestine. All these conditions of biliary tract will affect the absorption of fat.
Conditions affecting the pancreas may cause steatorrhea and they include pancreatic cancer, inflammation of pancreas or pancreatitis, cystic fibrosis, and abnormality in production of lipase by the pancreas present at birth. Steatorrhea is sometimes considered the basis for cystic fibrosis diagnosis. Most people with cystic fibrosis have problems with fat absorption since the disease interferes with the ability of pancreas to excrete digestive enzymes causing insufficiency of pancreatic lipase.
Steatorrhea may be short lived when is it is associated with infection and diet, but if it lasts for weeks and aggravates or get worse, it may be due to a serious condition. One may need to see a doctor especially if the there is black, tarry stool that floats, pus in stool, cramping or abdominal pain, and high fever.
Symptoms that may accompany steatorrhea
Steatorrhea presents in form of bulky stool that floats due to presence of fat. This condition may be accompanied by other symptoms. The symptoms will depend on the underlying condition, disorder, or disease causing the fat absorption problem.
Among the symptoms likely to be felt or seen are abdominal pain and cramping, diarrhea, gas, foul smelling stool, swelling of the abdomen, bloating, and distension. One may also experience nausea with vomiting or without vomiting. Pale feces may be seen.
Other symptoms likely to come with steatorrhea are dark urine, cough, unexplained weight loss, frequent infections, jaundice or yellowing of skin and the whites of eyes. Some symptoms may be life threatening such as bloody stool that is red, black, or tarry, passing out, chest tightness, high fever, problem with breathing, and sudden sharp pain in abdomen.
When you notice your stool is floating, you should seek medical help. When not treated, the causes for steatorrhea could lead to serious complications. Treatment depends on the cause of the problem. Tests may be conducted to determine what may be causing the fat absorption problem.
These are implied pictures of steatorhhea or fatty stool. They appear oily or greasy and have a tendency to float.