Before moving to metabolism, we are going learn about some common digestive problems.
- 5.1: Peptic Ulcers
- When the mucus layer of the stomach or duodenum becomes too thin, acid can erode the cells lining these tissues. This results in a lesion known as a peptic ulcer, as shown below.
- 5.2: Gallstones
- Gallstones are formed when bile hardens in the gallbladder. 80% of gallstones are a result of cholesterol precipitation, while 20% are a result of bile pigment precipitation. The cause of gallstones is unknown.
- 5.3: Irritable Bowel Syndrome
- Irritable bowel syndrome (IBS) is a group of symptoms, not a disease. In IBS, the colon does not function correctly. The symptoms of IBS are cramping, bloating, gas, diarrhea, and/or constipation. The cause of IBS is unknown.
- 5.4: Inflammatory Bowel Disease
- Inflammatory bowel disease (IBD) refers to a number of inflammatory conditions in the intestine. The two most common are Crohn's Disease and ulcerative colitis. These two conditions differ mainly in the areas of the intestine that are affected.
- 5.5: Celiac Disease
- People with celiac disease cannot consume the protein gluten because it causes their body to generate an autoimmune response (immune cells attack the body's own cells) that causes damage to the villi in the intestine.
- 5.6: Diverticulosis & Diverticulitis
- In diverticulosis, diverticula (plural, diverticulum singular), or outpouches, are formed at weak points in the large intestine, primarily in the lowest section of the sigmoid colon. It is believed that diverticula are formed as a result of a low-fiber diet because people may strain more during bowel movements.
- 5.7: Hemorrhoids
- Hemorrhoids are swollen or inflamed veins of the anus or lower rectum. An internal hemorrhoid occurs within the anus, while an external hemorrhoid occurs in the skin surrounding the anus. Symptoms of hemorrhoids include bleeding, pain during bowel movements, and/or itching. It is estimated that “about 75% of people will have hemorrhoids at some point in their lives”.
Thumbnail: Numerous small gallstones made up largely of cholesterol. Human gallstones, all removed in one patient. Grid scale 1 mm. Image used with permission (CC BY-SA 4.0; George Chernilevsky).