By the time the chyme has reached this tube, most nutrients and 90% of the water have been absorbed by the body. At this point some electrolytes like sodium , magnesium , and chloride are left as well as indigestible parts of ingested food (., a large part of ingested amylose , starch which has been shielded from digestion heretofore, and dietary fiber , which is largely indigestible carbohydrate in either soluble or insoluble form). As the chyme moves through the large intestine, most of the remaining water is removed, while the chyme is mixed with mucus and bacteria (known as gut flora ), and becomes feces. The ascending colon receives fecal material as a liquid. The muscles of the colon then move the watery waste material forward and slowly absorb all the excess water, causing the stools to gradually solidify as they move along into the descending colon . 
Methotrexate (MTX) is the antimetabolite most often prescribed by dermatologists for moderate-to-severe psoriasis. Hepatotoxicity is the primary clinical concern when planning long-term methotrexate therapy. Mild transaminase elevations (less than twice the upper limit of normal) are to be expected during therapy, but these levels do not correlate with hepatic fibrosis. A 2009 consensus conference advocates following the American College of Rheumatology guidelines for patients with no risk factors for liver injury and recommend considering liver biopsy or switching to another treatment after to 4 g to total cumulative methotrexate dosage. Folic acid (FA) supplementation at 1 mg daily is recommended to abate the gastrointestinal side effects of methotrexate without reducing efficacy (although many providers hold FA on the day of MTX therapy). It also helps to prevent megaloblastic anemia.