He has fecal incontinence so his external sphincter is damaged, which is innervated by the pudendal n. (S2-S4). The pelvic splanchnic nerves, which mediate the erection process, are also S2-S4.

S2,3,4 keeps the 3 P's off the floor (Penis, Poo, and Pee)

I took the approach of 10 year history DM --> Chronic DM complications = 1. Nonenzymatic Glycosylation (NEG) 2. Osmotic Damage.

Osmotic Damage can lead to neuropathy and autonomic degeneration. Fecal incontinence can be indicative of autonomic damage (parasympathetics = rest + digest = poop; There was a UWorld Q about constipation + parasympathetics - can't remember ID Sorry).

A. Dysuria --> Not related to NEG or osmotic damage

C. Inability to climb stairs --> Motor > sensory, so unlikely NEG or osmotic

D. Night-time leg cramps --> Claudication/PAD can present with symptoms that are worse at night when legs are horizontal with height, however this isn't cramping pain, which hints to an MSK problem or RLS.

E - Sciatica --> Not related to NEG or Osmotic Damage.

That leaves us with B --> Erections are obtained by pointing, shooting, and squeezing (parasympathetics, sympathetics, somatic). Impotence specifically is failure to obtain erection = failure to point = failure of parasympathetics = autonomic instability secondary to osmotic damage

Reference = FA2018 - page 344

We know that the defecation process is modulated by the parasympathetic and voluntary nervous systems, with tonic stimulation of the sympathetic nervous system (thank god, so we aren't just pooping and peeing with erections all the time).

S2,S3,S4 roots all provide input to the anal canal, urethral sphincters, and to the erectile apparatus.

We know that the pelvic splanchnic nerves, arise from these nerve roots (S2, S3, S4). Pelvic splanchnic nerves cause detrusor muscle contraction (urination), peristalsis in the hindgut (defecation), and mediate erection.

The other nerve that arises from S2,S3,S4 is the pudendal nerve, which mediates basically the same stuff, it mediates urination (ext. urethral sphincter relaxation), defecation (ext anal sphincter relaxation), and emission.

This question says that a patient with a 10 year history of DM Type 1 has fecal incontinence (presumably diabetic neuropathy) which of the following additional symptoms will this dude have? we know from our anatomy run down, that this is caused by damage to the pudendal nerve, who regulates the ext. anal sphincter, leading to fecal incontinence. The pudendal nerve is from S2,S3,S4 nerve roots so the diabetic neuropathy is occurring here. The only other answer choice with innervation from S2,S3,S4 is the pelvic splanchnic nerves which leads to erection, damage to the S2,S3,S4 nerve roots cause lack of erection or inability to maintain erection (impotence).