However, alkylation causes severe side-effects and is actually carcinogenic in its own right, with potential to lead to the development of secondary tumors. In a similar manner, arsenic-based medications like melarsoprol, used to treat trypanosomiasis, can cause arsenic poisoning. Adverse effects can appear mechanically. The design of some surgical instruments may be decades old, hence certain adverse effects (such as tissue trauma) may never have been properly characterized. Psychiatry
In psychiatry, iatrogenesis can occur due to misdiagnosis (including diagnosis with a false condition, as was the case of hystero-epilepsy). An example of a partially iatrogenic condition due to common misdiagnosis is bipolar disorder, especially in pediatric patients. Other conditions such as somatoform disorder and chronic fatigue syndrome are theorized to have significant sociocultural and iatrogenic components. Posttraumatic stress disorder is hypothesized to be prone to iatrogenic complications based on treatment modality. Even use of antipsychotic drugs leads to loss of brain mass.The psychiatric treatment of some conditions and populations, such as substance abuse are regarded as carrying risks for iatrogenesis. At the other end of the spectrum, dissociative identity disorder is considered by a minority of theorists to be a wholly iatrogenic disorder with the bulk of diagnoses arising from a tiny fraction of practitioners.The degree of association of any particular condition with iatrogenesis is unclear and in some cases controversial. The over-diagnosis of psychiatric conditions (with the assignment of mental illness terminology) may relate primarily to clinician dependence on subjective criteria.
Signs and symptoms
Depending on the level of obstruction, bowel obstruction can present with abdominal pain, swollen abdomen, abdominal distension, and constipation. Bowel obstruction may be complicated by dehydration and electrolyte abnormalities due to vomiting; respiratory compromise from pressure on the diaphragm by a distended abdomen, or aspiration of vomitus; bowel ischemia or perforation from prolonged distension or pressure from a foreign body.In small bowel obstruction, the pain tends to be colicky (cramping and intermittent) in nature, with spasms lasting a few minutes. The pain tends to be central and mid-abdominal. Vomiting may occur before constipation.In large bowel obstruction, the pain is felt lower in the abdomen and the spasms last longer. Constipation occurs earlier and vomiting may be less prominent. Proximal obstruction of the large bowel may present as small bowel obstruction. Causes
Small bowel obstruction
Causes of small bowel obstruction include:
Adhesions from previous abdominal surgery (most common cause)
Barbed sutures
Pseudoobstruction
Hernias containing bowel
Crohns disease causing adhesions or inflammatory strictures
Neoplasms, benign or malignant
Intussusception
Volvulus
Superior mesenteric artery syndrome, a compression of the duodenum by the superior mesenteric artery and the abdominal aorta
Ischemic strictures
Foreign bodies (e.g. gallstones in gallstone ileus, swallowed objects such as expandable water toys)
Intestinal atresiaAfter abdominal surgery, the incidence of small bowel obstruction from any cause is 9%. In those where the cause of the obstruction was clear, adhesions are the single most common cause (more than half).