Editing Malabsorption (section)

==Signs and symptoms==

===Gastrointestinal manifestations===
Depending on the nature of the disease process causing malabsorption and its extent, gastrointestinal symptoms may range from severe to subtle or may even be totally absent. [[Diarrhea]], [[weight loss]], [[flatulence]], abdominal [[bloating]], abdominal [[cramps]], and pain may be present. Although diarrhea is a common complaint, the character and frequency of stools may vary considerably ranging from over 10 watery stools per day to less than one voluminous putty-like stool, the latter causing some patients to complain of constipation. On the other hand, stool mass is invariably increased in patients with [[steatorrhea]] and generalized malabsorption above the normal with 150–200 g/day. Not only do unabsorbed nutrients contribute to stool mass but mucosal fluid and electrolyte secretion is also increased in diseases associated with mucosal inflammation such as [[coeliac disease]]. In addition, unabsorbed fatty acids, converted to hydroxy-fatty acids by colonic flora, as well as unabsorbed [[bile acid]]s both impair absorption and induce secretion of water and electrolytes by the colon adding to stool mass. Weight loss is common among patients with significant intestinal malabsorption but must be evaluated in the context of caloric intake. Some patients compensate for fecal wastage of unabsorbed nutrients by significantly increasing their oral intake. Eliciting a careful dietary history from patients with suspected malabsorption is therefore crucial. Excessive flatus and abdominal bloating may reflect excessive gas production due to fermentation of unabsorbed carbohydrate, especially among patients with a primary or secondary [[disaccharidase]] deficiency, such as [[lactose intolerance]] or [[sucrose intolerance]]. Malabsorption of dietary nutrients and excessive fluid secretion by inflamed small intestine also contribute to abdominal distention and bloating. Prevalence, severity, and character of abdominal pain vary considerably among the various disease processes associated with intestinal malabsorption. For example, pain is common in patients with chronic pancreatitis or pancreatic cancer and [[Crohn's disease]], but it is absent in many patients with coeliac disease or postgastrectomy malabsorption.<ref name="medline" />

===Extraintestinal manifestations===
Substantial numbers of patients with intestinal malabsorption present initially with symptoms or laboratory abnormalities that point to other organ systems in the absence of or overshadowing symptoms referable to the gastrointestinal tract. For example, there is increasing epidemiologic evidence that more patients with coeliac disease present with [[anemia]] and [[osteopenia]] in the absence of significant classic gastrointestinal symptoms. Microcytic, [[macrocytic anemia|macrocytic]], or dimorphic anemia may reflect impaired [[iron]], folate, or [[vitamin B12]] absorption. [[Purpura]], [[subconjunctival hemorrhage]], or even frank bleeding may reflect hypoprothrombinemia secondary to vitamin K malabsorption. Osteopenia is common, especially in the presence of [[steatorrhea]]. Impaired calcium and vitamin D absorption and chelation of calcium by unabsorbed fatty acids resulting in fecal loss of calcium may all contribute. If calcium deficiency is prolonged, secondary hyperparathyroidism may develop. Prolonged malnutrition may induce amenorrhea, infertility, and impotence. Edema and even ascites may reflect hypoproteinemia associated with protein losing enteropathy caused by [[lymphangiectasia|lymphatic obstruction]] or extensive mucosal inflammation. Dermatitis and peripheral neuropathy may be caused by malabsorption of specific vitamins or micronutrients and essential fatty acids.<ref>{{Cite journal|last=Fine|first=KD|last2=Schiller|first2=LR|date=1999|title=technical review on the evaluation and management of chronic diarrhea|journal=Gastroenterology|volume=116|issue=6|pages=1464–1486|doi=10.1016/s0016-5085(99)70513-5|pmid=10348832|s2cid=12239612}}</ref>

===Presentation===
[[File:Small-Intestine-highlighted.gif|thumb|Small intestine : major site of absorption]]
Symptoms can manifest in a variety of ways and features might give a clue to the underlying condition. Symptoms can be [[intestine|intestinal]] or extra-intestinal - the former predominates in severe malabsorption.{{citation needed|date=May 2022}}
* [[Diarrhoea]], often [[steatorrhoea]], is the most common feature.  Watery, diurnal and nocturnal, bulky, frequent stools are the clinical hallmark of overt malabsorption.  It is due to impaired water, [[carbohydrate]] and [[electrolyte]] absorption or irritation from unabsorbed [[fatty acid]]. The latter also results in [[bloating]], [[flatulence]] and abdominal discomfort.  Cramping pain usually suggests obstructive intestinal segment ''e.g.'' in [[Crohn's disease]], especially if it persists after defecation.<ref name="julio" />
* Weight loss can be significant despite increased oral intake of nutrients.<ref>health a to z{{Cite web|title=Malabsorption syndrome|url=http://www.healthatoz.com/healthatoz/Atoz/common/standard/transform.jsp?requestURI=/healthatoz/Atoz/ency/malabsorption_syndrome.jsp|url-status=dead|archive-url=https://web.archive.org/web/20070522222611/http://www.healthatoz.com/healthatoz/Atoz/common/standard/transform.jsp?requestURI=%2Fhealthatoz%2FAtoz%2Fency%2Fmalabsorption_syndrome.jsp|archive-date=2007-05-22|access-date=2007-05-10}}</ref>
* Growth retardation, failure to thrive, delayed [[puberty]] in children
* Swelling or [[oedema]] from loss of [[protein]]
* [[Anaemia]]s, commonly from [[vitamin B12|vitamin B<sub>12</sub>]], [[folic acid]] and [[iron deficiency (medicine)|iron deficiency]] presenting as fatigue and weakness, and the first of which can give rise to neuropsychiatric symptoms such as [[Paresthesia|abnormal sensations]], [[Ataxia|difficulty walking]], and decreased mental abilities.
* Muscle [[cramp]] from decreased [[vitamin D]], [[calcium]] absorption. Also lead to [[osteomalacia]] and [[osteoporosis]]
* Bleeding tendencies from [[vitamin K]] and other [[coagulation factor]] deficiencies.