Introduction to Gastrointestinal Medications and Nutrition
The GI tract is a complex system that includes the esophagus, stomach, small intestine, large intestine (colon), and rectum. The digestive system breaks down food into smaller molecules that the body can absorb.
Gastrointestinal nutrition is the study of how food is digested and absorbed in the body. Understanding how different nutrients affect the body is knowledge that a nurse applies in practice when caring for clients who have malnutrition from difficulty eating or digesting food.
Food nutrients are absorbed into the bloodstream by the walls of the small intestine. From there, they travel to other parts of the body to be used for growth and repair.
There are many prescribed and over-the-counter medications that can treat a wide variety of GI conditions. Nurses need to be aware of the wide variety of medications used for GI conditions and how each can affect their clients.
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Antiemetics
Antiemetics are medications that help prevent nausea and vomiting and are often used in treating GI conditions. Some antiemetics work by blocking receptors in the brain that detect motion sickness. Others work by blocking receptors in the stomach that detect chemicals released from the gut lining when it’s irritated or damaged by the contents of food or drinks consumed.
Some antiemetics can be taken orally, while others must be administered intravenously. It’s important to note that the best way to treat nausea and vomiting is prevention, if possible.
Ondansetron
Indication: Treating and preventing nausea and vomiting.
Mechanism of action: Blocking the action of serotonin, a cause of nausea and vomiting.
Side effects:
- Headache
- Constipation
- Abdominal discomfort
- Diarrhea
Metoclopramide
Indication: Treating nausea and vomiting in conditions such as gastroparesis and gastroesophageal reflux disease (GERD).
Mechanism of action: Increasing muscle contractions in the digestive system and stomach emptying time.
Side effects:
- Dry mouth
- Constipation
- Dizziness
- Drowsiness
- Blurred vision
- Headaches
Antispasmodics
Antispasmodics are a type of drug that help relax muscles in the GI tract. They can be used to treat a variety of conditions, including irritable bowel syndrome (IBS) and spastic colon.
Dicyclomine
Indication: Administered to clients with multiple loose stools per day – IBS (Irritable bowel syndrome).
Mechanism of Action: Relaxation of smooth muscle and drying out secretions.
Side effects:
- Dry body & mouth
- Constipation
- Urine retention
Anti-Inflammatory Drugs
Anti-inflammatory drugs are some of the most common medications used to treat gastrointestinal (GI) disorders. These drugs reduce inflammation in the digestive tract, which can help with symptoms like nausea, abdominal pain, and diarrhea.
Sulfasalazine
Indication: Administered to clients with Inflammatory bowel disease (IBD), Crohn’s disease, and Ulcerative Colitis.
Mechanism of Action: Decreases colon inflammation by stopping prostaglandins (a cause of inflammation).
Side effects: Yellow-orange discoloration of the client’s skin and urine.
Acid Prevention Drugs
Acid prevention drugs work by neutralizing stomach acid and keeping it from damaging the esophagus, stomach, or intestines.
Antacids
Although they’re not a scam, here’s a memory trick for memorizing antacids:
Sodium Bicarbonate
Calcium Carbonate
Aluminum Hydroxide
Magnesium Hydroxide
Mechanism of Action: Immediately and temporarily neutralizes stomach acid (NOT long-lasting).
Side effects:
- Diarrhea
- Constipation
- Stomach cramps
- Nausea
- Vomiting
H2 Blockers
H2 blockers end in “-tidine,” and include Ranitidine and Famotidine.
Indication: Administered to clients with GERD, ulcers, and duodenal & gastric prevention.
Mechanism of Action: Reduces gastric secretions by blocking H2 receptors in the stomach.
Side effects:
- Diarrhea
- Constipation
- Fatigue
- Drowsiness
- Headache
- Muscle aches
Proton Pump Inhibitors (PPIs)
PPIs typically end in “-prazole,” including Omeprazole, Esomeprazole, and Pantoprazole.
Indication: Administered for stress ulcer prevention, GERD, and heart-burn.
Mechanism of Action: Inhibits proton pump in the stomach’s parietal cells to reduce gastric acid.
Side effects:
- Headache
- Rash
- Dizziness
- Nausea
- Abdominal pain
- Constipation
- Diarrhea
Mucosal Protectants
Mucosal protectants are drugs that help soothe and protect the inner lining of the GI tract.
Sucralfate
Indication: Given to treat and prevent both stomach and duodenal ulcers (small intestines).
Mechanism of Action: Forms a thick protective layer over ulcers to provide a physical barrier against stomach acids & enzymes.
Side effects:
- Constipation
- Diarrhea
- Nausea
- Vomiting
- Itching
- Dizziness
- Drowsiness;
- Sleep problems (insomnia)
Misoprostol
Indication: Protects clients against gastric ulcers.
Mechanism of Action: Synthetic prostaglandin that increases protective mucous inside the stomach.
Side effects:
- Diarrhea
- Stomach cramps
- Nausea
Herbal Supplements (with Memory Tricks)
Herbal supplements are becoming more popular as a treatment for gastrointestinal (GI) issues, and are used in combination with traditional medicine. These supplements are taken orally and, in some cases, even available over the counter. All herbal supplements need to be used with caution when taking other medications.
Herbal supplements can be used for various conditions such as:
Joints
Glucosamine
- Watch for hypoglycemia when taking anti-diabetic meds.
Prostate
Saw Palmetto – Treats benign prostatic hyperplasia (BPH).
- SP – Swollen Prostate
Menopause
Black Cohosh
- Bad CoHOT flash
Heart
Hawthorn extract
- Hawthorn
Mental (Depression & Insomnia)
Valerian
- Valium effects
St. John Wort
- Affects:
- Serotonin (caution)
- Stay away from antidepressants
- It interferes with a variety of medications
Skin
- Evening Primrose
- Ginkgo
- Biloba
- Ginseng Omega 3
- Garlic

During my exam, I could literally see and hear him going over different areas as I was answering my questions.
This past Friday I retook my Maternity Hesi and this time, I decided for my last week of Holiday break to just watch all of his OB videos. I am proud to say that with Mike’s help I received a score of 928 on my Maternity Hesi!

Gastrointestinal Medications Conclusion
Nurses must be knowledgeable about medications to assist clients in managing their medication regimens safely.
Some of the most popular medications for treating gastrointestinal (GI) problems include anti-inflammatory drugs. These medications reduce digestive system inflammation, easing symptoms like nausea, abdominal pain, and diarrhea.
Antiemetics are drugs that reduce nausea and vomiting and are frequently prescribed for GI problems. Antispasmodics help GI tract muscular relaxation, and can help treat several conditions, such as spastic colon and irritable bowel syndrome (IBS).
Combining herbal supplements with conventional therapy is a growing trend in treating gastrointestinal (GI) problems. These supplements are consumed orally, and are sometimes sold without a prescription.
Sources
https://www.hopkinsmedicine.org/health/conditions-and-diseases/medicines-and-the-digestive-system
https://www.ncbi.nlm.nih.gov/books/NBK532303/
https://my.clevelandclinic.org/health/drugs/15829-herbal-supplements




