Brief Answer:
Faulty diet,lifestyle/ inflammation, infection/ hormones/medication.

Detailed Answer:
Hi XXXXXXX Blevins70,
Thanks for the query,
Hard & triangular shaped clusters in stool indicate sever constipation.. which makes routine life disturbed & uneasy. I understand your concern.
* basically such type of stool can appear when--
1. - There is less of water content in stools . This can happen when-
- Water & fiber content of diet is not sufficient. un absorbable fibers in food remain un absorbed in gut.. & it swells up when sufficient water is ingested.. to make stools soft & also gives volume to the stools, helps peristalsis ( movement of large intestine ) to clear bowels easily.
2. - The same problem will happen when stools lies in large bowel for longer time..( this can be due to lack of exercises/ less muscular or nerve activities in gut.. like in diabetes, old age, hypothyroidism .
- Certain medicines like antacids, iron, anti depressants - make stools dry .. by increasing water absorption from stool/ or lessening intestinal movements.
- Some growth/ obstruction in intestinal passage can cause it.
3. - Bowel inflammation/ infection ( Bacterial, amoebic, worms )hamper movements of intestine, the excess mucus production in such cases make stools sticky & difficult to move.
- Anal-rectal problems like piles, fissure leads to avoidance of defecation due to fear of pain/ bleeding & thus causes delayed , hard motions.
- eating excess of fast food/ dairy products also reduces less & sticky stool formation.
4. Lifestyle problems - Irregular dietary & bowel habits/ sedentary life style/ psychological stress & tension can affect bowel movements to cause hard & small triangular stools.
All these are the possible causes for hard , triangular clusters in stools.
I hope the answer was both informative & useful for you. Any follow up query is welcome.
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Thanks.

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