How does hyponatremia cause increased motility and hyperactive bowel sounds?

[Vani1925]

So I'm studying fluids and electrolytes for my test next week. For me knowing the rationale of things is what helps me remember and study best, but I came across the signs and symptoms of some electrolytes imbalances and for some of them they do not have a rationale. It is really annoying to me because I just can't try to memorize them because I will not remember. I need something to relate it to. I need the why and I have been looking everywhere and can't find the answers. So here it is:

* in my book it says: "intestinal changes include increased motility, causing nausea, diarrhea, and abdominal cramping". I do not understand why if with hyponatremia there is reduced excitability of the membranes. I mean hypokalemia also causes decreased membrane excitability, yet with potassium you get decreased motility, which totally makes sense to me. Does anyone know the rationale behind hyponatremia causing decreased motility?

*Whywould hypocalcemia cause hypotension. If it causes hyperexcitibility of muscleswouldn't it make the heart beat faster and increase blood pressure and pulse? Whywould the opposite happen in hypercalcemia if there is less sensitivity tostimulus? All my book says is this: "The heart may be slower or slightly faster than normal, with weak, thready pulse. Severe hypocalcemia causes severe hypotension and ECG changes of a prolonged ST interval and a prolonged QT interval." This does not make any sense to me at all. O_o

TIA

[pmabraham, BSN, RN]

Anytime you have stomach cramping, you have hyperactive bowel sounds.

[Vani1925]

Thank you. I understand that, but what I don't understand is what are the changes that cause the abdominal cramping that will lead to the hyperactive sounds. For the other electrolytes that I studied for if you have decreased excitability you get decreased or absent bowel sounds, and you get constipated, because you have that decreased excitability, yet for this one you have decreased excitability and increased bowel sounds. That is what does not make sense to me.

[pmabraham, BSN, RN]

The way I understand it is via the KISS principal of keep it simple and smile. I focus on whether or not there is abdominal cramping (rather than motility) as it relates to hyperactive bowel sounds. Check out Hyponatremia Sign Causes Symptoms and Treatment | PubMedi -- increased bowel motility (not decreased).

[Vani1925]

Ok Thanks!