Colic (from Greek κολικός "kolikos", "relative to the colon") or cholic is a form of pain that starts and stops abruptly. It occurs due to muscular contractions of a hollow tube (colon, ureter, gall bladder, etc.) in an attempt to relieve an obstruction by forcing content out. It may be accompanied by vomiting and sweating. Types include:

- Baby colic, a condition, usually in infants, characterized by incessant crying

- Renal colic, a pain in the flank, characteristic of kidney stones

- Biliary colic, blockage by a gallstone of the common bile duct or cystic duct

- Horse colic, a potentially fatal condition experienced by horses, caused by intestinal displacement or blockage

- Devon colic, an affliction caused by lead poisoning

- Painter's colic or lead poisoning

In humans, enteroliths are rare and may be difficult to distinguish from gall stones. Their chemical composition is diverse, and rarely can a nidus be found. A differential diagnosis of an enterolith requires the enterolith, a normal gallbladder, and a diverticulum.

An enterolith typically forms within a diverticulum. An enterolith formed in a Meckel's diverticulum sometimes is known as a Meckel's enterolith. Improper use of magnesium oxide as a "long-term" laxative has been reported to cause enteroliths and/or medication bezoars.

Most enteroliths are not apparent and cause no complications. However, any complications that do occur are likely to be severe. Of these, bowel obstruction is most common, followed by ileus and perforation. Bowel obstruction and ileus typically occur when a large enterolith is expelled from a diverticulum into the lumen. Perforation typically occurs within the diverticulum.

Most human enteroliths are radiolucent on plain X-rays. They sometimes can be visualized on CT scans without contrast; presence of contrast in the lumen may reveal the enterolith as a void. Most often, they are visualized using ultrasound.

Although recent surveys of enterolith composition are lacking, one early review notes struvite (as in equines), calcium phosphate, and calcium carbonate and reports choleic acid. Deoxycholic acid and cholic acid have also been reported.

In simple cases of obstruction, where there are no complications, a variety of non-surgical and surgical techniques are used to remove the enterolith. These include crushing the enterolith and milking it back to the stomach or forward to the colon, surgical removal via an uninvolved segment of the gastrointestinal tract, and resection of the involved segment.