Answer to Question 1
Unknown cause
Genetic predisposition: Genes that control serotonin receptors may make certain people more prone to IBS
Gender: Affects more women than men
Altered immune response stimulated by food sensitivity
Patients may be able to identify certain foods that exacerbate symptoms
Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols or sugar alcohols (FODMAPs) may play a role in the development of IBS
Altered microbial environment in the colon
- Abnormal colonic fermentation (partial digestion of food in the large intestine that may lead to excessive gas production as a by-product)
- Includes small intestine bacterial overgrowth
Elevated inflammatory response to gastroenteritis (infection)
Specific bacteria documented with gastroenteritis in the development of IBS:
Salmonella
Blastocystis hominis
Campylobacter
Parasites like Trichinella spiralis
Heightened or abnormal communication between GI tract and muscle
Increased sensitivity to the enteric system that changes motility
- Stimuli that most people would not react to cause symptoms of urgency, diarrhea, or constipation in IBS patients
- Stress and other psychological factors may exacerbate symptoms
Commonly associated with celiac disease, Inflammatory bowel disease - not causes but these often co-exist with IBS.
Abnormal release, transport, or recognition of serotonin
- 95 of serotonin is found in the GI tract, and serotonin can be either stimulatory or inhibitory to the GI tract, which is why people may have diarrhea, constipation, or a mix with IBS.
- Serotonin can either cause stimulation of acetylcholine, which causes muscle contraction, or it can cause release of nitric oxide, which relaxes smooth muscle in the GI tract.
- Altered serotonin levels are well documented in IBS patients.
Documented reduced levels of serotonin in IBS-C patients
Documented elevated levels of serotonin in IBS-D
Although there is documentation, the exact role of serotonin in IBS is not understood
Altered GI mucosal permeability may be caused by these previously discussed triggers and lead to inflammation and an altered perception of pain.
Answer to Question 2
Calculating Mr. Perez's BMI):
Admission weight: 102.7 kg; height: 70
BMI: 102.7 kg/(1.778 m2) = 32.4 kg/m2 (>30 is classified as obese)
IBW: 75.5 kg; IBW: 136
Current weight: 109 kg; BMI: 34.5 kg/m2 (>30 is classified as obese)
IBW: 144
Based on his admission and day 7 weight, Mr. Perez is obese for his height. He is also at 136-144 of his ideal body weight. In order to prevent overfeeding this patient, it is appropriate to estimate his energy and protein needs using his ideal body weight in order to most accurately match his nutritional needs.