CSID is an inherited condition characterized by a dysfunctional digestive enzyme.The purpose of the digestive enzyme, sucrase-isomaltase, is to break down the compound sugars sucrose (table sugar) and starch sugars so they will be small enough to be absorbed from the gastrointestinal tract.In addition to CSID, a primary gastrointestinal disorder such as a gastrointestinal infection, celiac disease or Crohn’s disease, can transiently suppress the digestive function of sucrase-isomaltase, causing an acquired form of sucrase-isomaltase deficiency (SID). Once the underlying disorder is treated and resolved, the symptoms of SID usually go away.A deficiency or absence of sucrase-isomaltase function is likely to cause chronic gastrointestinal symptoms whenever a person eats food containing sucrose or starch sugars, which are very common in carbohydrates. In fact, the sucrase-isomaltase enzyme is responsible for the digestion of all foods containing sucrose and approximately 60% to 80% of all foods containing starch sugars. When sucrose or starch sugars are not absorbed from the gastrointestinal tract, they travel to the large intestine (colon) where two things happen:
The food draws in excess water by a process called osmosis, creating watery diarrhea. The food is broken down by the normal bacteria that reside in the colon by a process called fermentation; byproducts of all fermentation include the production of excess gas and an acidic environment.The timing of gastrointestinal symptoms associated with CSID is distinctive. CSID symptoms are frequent, daily events; they are lifelong, and they are postprandial (occurring after eating food).
If TSH levels are elevated, hyperprolactinemia is secondary to hypothyroidism and treated accordingly. If TSH levels are normal, an MRI or CT scan is conducted to assess for any pituitary adenomas. Although hyperprolactinemia is often uncommon in postmenopausal women, prolactinomas detected after menopause are typically macroadenomas. While a plain X-ray of the bones surrounding the pituitary may reveal the presence of a large macroadenoma, small microadenomas will not be apparent. Magnetic resonance imaging (MRI) is the most sensitive test for detecting pituitary tumors and determining their size. MRI scans may be repeated periodically to assess tumor progression and the effects of therapy. Computed Tomography (CT scan) is another indicator of abnormalities in pituitary gland size; it also gives an image of the pituitary, but is less sensitive than the MRI. In addition to assessing the size of the pituitary tumor, physicians also look for damage to surrounding tissues, and perform tests to assess whether production of other pituitary hormones are normal. Depending on the size of the tumor, physicians may request an eye exam that includes the measurement of visual fields.However, a high measurement of prolactin may also result from the presence of macroprolactin, otherwise known as big prolactin or big-big prolactin, in the serum. Macroprolactin occurs when prolactin polymerizes together and can bind with IgG to form complexes. Although this can result in high prolactin levels in some assay tests, macroprolactin is biologically inactive and will not cause symptoms typical of hyperprolactinemia.