This link will take you to a web md glossary of terms where the explanation is full and is easy to understand http://www.webmd.com/digestive-disorders/digestive-diseases-glossary-terms.
The following is a smaller list of terms you may frequently come across around Gut disease.
Bacteria
Very small organisms (microbes) that are normally in the gut (intestines). There are over 500 different kinds known to live in the gut; most (up to several billion) bacteria are in the large intestine (colon). “Normal” bacteria have important functions in life and health. Bacteria that can cause infection are called “pathogens.” Normal bacteria protect against pathogens.
Bile
Secretions of the liver that aid in digestion and absorption of nutrients in the intestinal tract.
Celiac disease
Inability to digest and absorb the protein gliadin (a component of gluten). Gliadin is found in wheat, rye, barley, and oats. Celiac disease is also called celiac sprue, and gluten intolerance.
Cholecystectomy
Surgical removal of the gallbladder.
Colectomy
Removal of part or all of the colon.
Colitis
Inflammation of the colon.
Colon
The large intestine.
Colonoscopy
Colonoscopy is a fiberoptic (endoscopic) procedure in which a thin, flexible, lighted viewing tube (a colonoscope) is threaded up through the rectum for the purpose of inspecting the entire colon and rectum and, if there is an abnormality, taking a tissue sample of it (biopsy) for examination under a microscope, or removing it.
Colostomy
A surgically created opening of the colon to the abdominal wall, allowing the diversion of fecal waste.
Crohn’s disease
A chronic form of inflammatory bowel disease.
Diarrhea
Passing frequent and/or loose or watery stools. Acute diarrhea goes away in a few weeks, and becomes chronic when it lasts longer than 4 weeks.
Gastroenteritis
An infection or irritation of the stomach and intestines.
Gastroenterologist
A doctor who specializes in digestive diseases or disorders.
Gastroenterology
The field of medicine concerned with the function and disorders of the digestive system.
Gastrointestinal (GI) tract
The muscular tube from the mouth to the anus, also called the alimentary canal or digestive tract.
Intestines
Also known as the gut or bowels, is the long, tube-like organ in the human body that completes digestion or the breaking down of food. They consist of the small intestine and the large intestine.
Irritable bowel syndrome (IBS)
A functional bowel disorder in which abdominal discomfort or pain is associated with a range of symptoms. Typically, these include intermittent abdominal pain accompanied by diarrhea, constipation, or alternating episodes of both.
Large intestine
The long, tube-like organ that is connected to the small intestine at one end and the anus at the other. The large intestine has four parts: cecum, colon, rectum, and anal canal. Partly digested food moves through the cecum into the colon, where water and some nutrients and electrolytes are removed. The remaining material, solid waste called stool, moves through the colon, is stored in the rectum, and leaves the body through the anal canal and anus.
Protocol
An action plan for a clinical trial. The plan states what the study will do, how, and why. It explains how many people will be in it, who is eligible to participate, what study agents or other interventions they will be given, what tests they will receive and how often, and what information will be gathered.
Random allocation
A method where all participants in a study have the same chance of being assigned to a study group, rather than allocation being assigned by the investigators,
Randomized controlled trial
A study in which people are allocated at random to receive one of several clinical interventions. One intervention is regarded as a standard of comparison or control.
Ulcerative colitis
A form of inflammatory bowel disease that causes ulcers and inflammation in the inner lining of the colon and rectum.